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# Glossaire

Accelerometer

An accelerometer is a sensor that measures the acceleration of the object on which it is installed. It is generally used to detect the movements and position changes of an object in space.
Accelerometers are commonly used in portable electronic devices, such as cell phones and laptop computers, to detect the position of the device and change the orientation of the screen accordingly. They are also used in navigation devices, toys and drones to detect movement and changes in direction.
The first accelerometers were invented in the early 20th century and were used to measure acceleration and vibration in industrial and military applications. They used springs and moving masses to detect acceleration. For example, the spring torsion accelerometer, invented in 1920 by German physicist Albert Kahmen, used a spring and a moving mass to detect acceleration.
During the 1960s and 1970s, electromechanical accelerometers began to be used, which used electrical sensors to measure acceleration instead of mechanical mechanisms. These electromechanical accelerometers have been used in guidance systems for missiles and space vehicles, as well as in instruments for measuring acceleration in civil engineering and soil mechanics.
Today, most accelerometers are miniaturized electronic sensors, which use micro-machine technologies to measure acceleration. These sensors are widely used in portable electronic devices, navigation devices and industrial motion sensors.

Acoustic beat

An acoustic beat is a sound phenomenon that occurs when two sound waves of close frequencies are emitted simultaneously. The combination of sounds is manifested by regular variations in the pitch of the sound, called beats. These pitch variations are caused by constructive and destructive interference between the two sound waves. Acoustic beats are usually audible when the two sound waves are very close in frequency, but they can also be seen in other types of waves, such as light waves. The formula for calculating beat frequency is: beat frequency = wave 1 frequency - wave 2 frequency. Acoustic beats are used in various fields such as medicine, metrology and acoustic engineering. The discovery of acoustic beats is attributed to Christian Doppler, who published his theory in 1842.

Addition of colors

The additive color method describes how colors are created by combining different primary color light sources. The primary colors used in the additive method are red, green and blue (RGB in English). When these primary colors are combined in equal proportions, they produce white light. If one increases the proportion of one of the primary colors in relation to the others, the light produced will have a corresponding hue. For example, if we increase the proportion of red in relation to green and blue, the light produced will be magenta in color. The additive color method is used in many areas that use light sources, such as the display of computer monitors, televisions, projectors, traffic lights, vehicle lights, and stage lights. Colors are usually created using light emitting diodes (LEDs) or liquid crystals (LCDs) which can produce different colors by adjusting the proportions of red, green and blue light.

Arduino

Arduino is an open-source microcontroller-based development platform that allows users to create interactive projects with sensors, actuators, and electronic devices. It is often used in robotics, home automation, Internet of Things (IoT) projects, music creation, and many other projects that require interaction between users and the environment. To use an Arduino, you must have an Arduino board, a computer with Arduino integrated development (IDE) software installed, and a series of electronic components such as sensors, actuators, and cables to connect the components to the Arduino board. . Once you have all the necessary components, you can use the Arduino IDE to write code for your project. The code is written using a programming language similar to C++. You can use Arduino's built-in libraries to access the functionality of various sensors and actuators. The code is then uploaded to the Arduino board using a USB cable. Once the code is uploaded to the board, the Arduino board uses the code to control the various electronic components connected to it. Users can then interact with the project by using the sensors to read data from the environment and by using the actuators to perform actions such as turning on an LED or operating a motor.

Atwood machine

Atwood's machine is an experimental device used to study the principles of classical mechanics, in particular the laws of conservation of energy and momentum. It consists of two masses attached to a rope that passes through a pulley. One of the masses is fixed while the other is free to move. Atwood's machine is used to show how the potential energy and kinetic energy of a system vary when masses are in motion, and how these energies are related to velocity and acceleration. The formula used to calculate the acceleration of the machine is: a = (m1-m2)/(m1+m2)g, where m1 and m2 are the masses of the objects and g is the acceleration due to gravity. The Atwood machine was invented by English mathematician and physicist George Atwood in the early 18th century. He used it to study the principles of Newtonian mechanics, which describe how forces act on moving objects. It has become a staple tool for teaching physics due to its simplicity and ability to clearly show the mechanical principles involved.

Beer-Lambert law

The Beer-Lambert law is a physical law that describes how the amount of light energy from a source passes through a transparent substance. It establishes a relationship between the intensity of the incoming light, the intensity of the outgoing light and the concentration of the substance through which the light passes. It is formulated as follows: I = I0 * e^(-kcx) where I is the outgoing light intensity, I0 is the incoming light intensity, k is the absorption constant of the substance, c is the concentration of the substance and x is the thickness of the substance. The Beer-Lambert law is used in many fields, including spectrophotometry, which is a technique used to measure the concentration of chemical substances using light. It is used to analyze blood, urine and tissue samples to detect diseases, infections and metabolic disorders. It is also used to analyze materials for optical properties, for industrial applications such as the manufacture of glass products and pigments.

Biomechanics

Biomechanics is a field of mechanical engineering that focuses on the movement of a living body. It analyses how muscles, tendons, ligaments and bones, work together to create movement. It is used to help athletes improve their movements in competition but also to study robotics or help older people do difficult tasks.

Chronophotography

Chronophotography is a photographic technique that involves capturing images of a moving subject at regular time intervals and superimposing them on the same image. We therefore see in a single image the entire movement of an object or a living being. The history of chronophotography goes back to the beginnings of photography, with the first experiments carried out in the middle of the 19th century by scientists and inventors such as Eadweard Muybridge and Étienne-Jules Marey. Muybridge in 1878 made a series of photographs of moving horses using an automatic trigger device to take pictures at regular time intervals. Marey meanwhile, in 1882, developed a device he called animal photographer , which used continuous film to capture moving images at a speed of 12 frames per second. These early experiments led to the invention of the motion picture camera, which made it possible to capture moving images at higher frame rates. Today, chronophotography is used in many fields, including scientific research, medicine, sports, and cinematic special effects.

Colorimeter

A colorimeter is a device used to measure the color of an object or surface. It typically uses a monochromatic light source (i.e. of a single wavelength) to illuminate the object, and measures the amount of reflected or transmitted light at different wavelengths. FizziQ's colorimeter uses a mobile phone's camera to measure colors in ambient light.
Colorimeters are often used in research and development laboratories to measure the color properties of materials, such as pigments, dyes, and coatings. They are also used in the printing industry to ensure that printed colors match the colors specified in print files. Additionally, colorimeters are used in photography and video to help adjust the color settings of image capture devices.

Decibel

The decibel (dB) is a unit of measurement used to express sound intensity or electrical signal strength. It is based on a decimal logarithm of the ratio of the measured value to a reference value.
For example, the normal sound intensity of a human conversation is between 60 and 70 dB. An aircraft taking off nearby can reach noise levels of 120 dB or more, which is very loud. A 10 dB increase represents approximately a 10-fold increase in loudness or signal strength. For example, if a sound is 10 times louder than another, it will be perceived as being 2 times louder than the other, which corresponds to an increase of 3 dB.
The decibel is often used to measure noise, but it is also used in other areas, such as measuring signal strength in radio or telecommunications, or even to measure the brightness of stars.

Doppler effect

The Doppler effect is a physical phenomenon discovered by Christian Doppler in 1842, which occurs when the source of a sound or an electromagnetic wave moves relative to an observer. It results in a variation of the frequency perceived by the observer, which is higher when the source approaches and lower when the source moves away. This effect is used in many fields, including meteorology, astronomy and medicine. The formula to calculate the Doppler effect is: f' = f(c+v_s)/(c+v_o) where f is the frequency of the source, c is the speed of light, v_s is the speed of the source and v_o is the speed of the observer.

Elastic collision

An elastic collision is a type of collision in which the two colliding bodies deform elastically and retain their initial kinetic energy. This means that the two bodies bounce against each other without losing energy.
An example of elastic shock is the motion of two billiard balls colliding. If the two balls are in motion when they collide and bounce against each other without losing energy, the collision is elastic.
The formula for kinetic energy before and after an elastic shock can be written as follows:
Kinetic energy before = Kinetic energy after
Where "Kinetic energy before" is the kinetic energy of the two bodies before the impact, and "Kinetic energy after" is the kinetic energy of the two bodies after the impact.
It is important to note that in an elastic shock, kinetic energy is conserved, but potential energy and elastic energy can be converted into each other.

Elastic energy

Elastic energy is the energy stored in a body when it is elastically deformed, that is, when it returns to its original shape when the force that deforms it is removed.
The formula for elastic energy depends on the force exerted on the body and the distance traveled under the action of this force. For a body subjected to an elastic force, the formula of the elastic energy can be written as follows:
Elastic energy = 1/2 * elastic constant * displacement^2
Where "elastic constant" is a constant that depends on the material of the body and its shape, and "displacement" is the distance traveled under the action of the elastic force.
It is important to note that the elastic energy is not an absolute quantity, but rather a difference in the amount of energy between two positions. Therefore, it is necessary to choose a reference level to determine the elastic energy of a body. Most often, the reference level chosen is the initial position of the body before it was deformed, so that the elastic energy of this body is equal to zero.

Energy Conservation

The law of conservation of energy is a fundamental principle of physics which states that energy cannot be created or destroyed, only converted from one form to another or moved from one place to another. This means that the total energy of an isolated system remains constant over time. When an object falls from a height, it acquires kinetic energy as it falls due to the force of gravity, on the other hand the potential energy related to its position decreases. The object's total energy remains constant, however, because the kinetic energy gained during the fall equals the potential energy lost. When a car travels on a road, the energy in its tank in the form of fuel is converted into kinetic energy which drives the car forward and into the frictional energy of the air on the car. When the car brakes and stops, this kinetic energy is converted into heat, which is dissipated into the environment. The total energy of the car remains constant, however, because the energy produced by the fuel used to move the car is equal to the heat energy lost when stopping and air friction during travel. .

Free fall

Free fall is the movement of a body subject only to the influence of gravity, without any air resistance or any other type of force. This means that if an object subject to the earth's attraction is dropped into an empty space, it will continue to fall indefinitely with a constant acceleration of 9.8 m/s² (1 g).
The concept of free fall was discovered by Italian scientist Galileo Galilei in the early 17th century. He also established the fundamental law of dynamics that all bodies fall with the same acceleration regardless of their mass. This law is known as "Galileo's Law of Free Fall".
The mathematical formula for calculating the distance traveled by an object in free fall is:
d = 1/2 * g * t²
where d is the distance traveled (in meters), g is the acceleration of gravity (9.8 m/s²) and t is the elapsed time (in seconds).
For example, if an object is dropped from the top of a 100 meter tower and falls for 5 seconds, the distance traveled will be:
d = 1/2 * 9.8 * 5² = 122.5 meters
The speed at which the object will hit the ground will be:
v = g * t = 9.8 * 5 = 49 m/s

Galilean frame of reference

Galilean frame of reference is a frame of reference in which the principle of inertia is verified, i.e. any point body on which no force is exerted or on which the resultant of the forces is zero is in rectilinear translation motion uniform, or at rest. The history of Galilean theory dates back to the 17th century, when Galileo Galilei began to study the movements of celestial bodies using instruments such as the astronomical telescope. He discovered that celestial bodies followed simple laws of motion, independent of their position in space, and that these laws were independent of the observer. These discoveries led to the formulation of the first modern theory of mechanics, known as Galilean mechanics which describes how bodies move under known forces. A common example of using a Galilean frame is to describe the movements of celestial bodies in space, such as satellites and planets. It is also used to describe the movements of objects on Earth, such as ground vehicles and aircraft. It is important to note that in the context of modern physics, the Galilean frames of reference are no longer considered as absolute frames of reference but rather as approximate frames of reference because they do not take into account certain relativistic effects.

Gravitational law

The Law of Gravitation is a physical law that describes the gravitational attraction between two bodies. It states that all bodies in the universe are attracted to each other with a force proportional to their mass and inversely proportional to the square of the distance between them.
The law of gravity was discovered by English scientist Isaac Newton in the 17th century. He also developed the mathematical formula that describes it:
F=G*(m1*m2)/d²
where F is the gravitational force (in newtons), G is the gravitational constant (6.67 × 10^-11 N.m²/kg²), m1 and m2 are the masses of the two bodies (in kg) and d is the distance between them (in meters).
An example of this law is the gravitational attraction between the Earth and the Moon. The gravitational force between these two bodies can be calculated using the above formula. If the mass of the Earth is 5.97 × 10^24 kg and that of the Moon is 7.35 × 10^22 kg, and if the average distance between these two bodies is 3.84 × 10^8 meters, then the gravitational force acting between them is:
F = 6.67 × 10^-11 * (5.97 × 10^24 * 7.35 × 10^22) / (3.84 × 10^8)² = 1.23 × 10^20 N
According to Albert Einstein's theory of general relativity, gravitation is not a force that pulls bodies together, but rather a curvature of spacetime caused by the presence of mass or d 'energy. When a massive body, like a planet or a star, is present in the universe, it "digs" a kind of ""hole"" in space-time due to its mass. The other bodies which are near this hole, like satellites or objects in free fall, are attracted towards it by following the curve of space-time. This is what creates the gravitation effect.
Einstein developed an equation to describe this curvature of spacetime, known as the equation of general relativity. This equation predicts with great precision many phenomena observed in the universe, such as the deflection of light by the Sun and the precession of the perihelions of the planets of the solar system. The theory of general relativity is one of the most important and successful theories in modern physics.

Gravity

Gravity is a force that pulls each massive body towards each other. It is responsible for the fall of objects towards the ground and the elliptical trajectory of celestial bodies around their star.
Gravity was theorized by English astronomer and physicist Isaac Newton in the 17th century. Newton relies on the work of Galileo who observed that all objects fall to the ground at the same speed, regardless of their mass. Newton had the intuition that this was due to a universal gravitational force exerted by the Earth. Newton also formulated the laws of mechanics which describe the movement of bodies under the influence of gravity. According to these laws, the gravitational force between two bodies is proportional to their mass and the distance between them, and it always acts along a line that connects the centers of mass of the two bodies. Later, German physicist Albert Einstein developed the theory of general relativity, which provides a more accurate description of gravity by taking into account the effects of the speed of light and the curvature of spacetime. According to this theory, gravity is the result of the curvature of spacetime caused by the mass and energy of bodies. "
"Kinetic energy is the energy that a moving object possesses. It is directly related to its speed and mass, and can be calculated using the following formula:
Kinetic energy = 1/2 * mass * velocity^2
The heavier an object is and the faster it moves, the more kinetic energy it has.
An example of kinetic energy is the movement of a soccer ball kicked by a player. When the ball is kicked, it acquires kinetic energy due to the force exerted by the player's foot, which gives it high speed. The higher the speed of the ball, the more kinetic energy it has.
"The Law of Gravitation is a physical law that describes the gravitational attraction between two bodies. It states that all bodies in the universe are attracted to each other with a force proportional to their mass and inversely proportional to the square of the distance between them.
The law of gravity was discovered by English scientist Isaac Newton in the 17th century. He also developed the mathematical formula that describes it:
F=G*(m1*m2)/d²
where F is the gravitational force (in newtons), G is the gravitational constant (6.67 × 10^-11 N.m²/kg²), m1 and m2 are the masses of the two bodies (in kg) and d is the distance between them (in meters).
An example of this law is the gravitational attraction between the Earth and the Moon. The gravitational force between these two bodies can be calculated using the above formula. If the mass of the Earth is 5.97 × 10^24 kg and that of the Moon is 7.35 × 10^22 kg, and if the average distance between these two bodies is 3.84 × 10^8 meters, then the gravitational force acting between them is:
F = 6.67 × 10^-11 * (5.97 × 10^24 * 7.35 × 10^22) / (3.84 × 10^8)² = 1.23 × 10^20 N
According to Albert Einstein's theory of general relativity, gravitation is not a force that pulls bodies together, but rather a curvature of spacetime caused by the presence of mass or d 'energy. When a massive body, like a planet or a star, is present in the universe, it "digs" a kind of ""hole"" in space-time due to its mass. The other bodies which are near this hole, like satellites or objects in free fall, are attracted towards it by following the curve of space-time. This is what creates the gravitation effect.
Einstein developed an equation to describe this curvature of spacetime, known as the equation of general relativity. This equation predicts with great precision many phenomena observed in the universe, such as the deflection of light by the Sun and the precession of the perihelions of the planets of the solar system. The theory of general relativity is one of the most important and successful theories in modern physics.

Gyroscope

gyroscope is a device that uses the effect of conservation of angularity to maintain a stable axis of rotation with respect to an external frame of reference. It was invented in 1817 by Jean-Bernard-Léon Foucault, a French physicist. The history of the gyroscope goes back to the beginnings of classical physics, where it was used to demonstrate the rotation of the Earth. In 1852, Foucault used a large spinning pendulum to prove that the Earth rotated, which revolutionized our understanding of our planet. The first practical applications of the gyroscope were for rotating compasses, used for sea and air navigation. Gyroscopes have also been used to maintain stability in vehicles, such as wheeled vehicles and aircraft, as well as attitude control systems for satellites and space vehicles. The formula that describes the behavior of a gyroscope is the precession equation, which describes how the angle of precession varies with moment of inertia, angular velocity, and tracking force applied to the axis of rotation: Ωp = (L x Ω) / I Where Ωp is the angular velocity of precession L is the angular momentum of the object Ω is the angular velocity of initial rotation I is the moment of inertia of the object An example A common use for a gyroscope is in platform stabilization systems, such as stabilization systems for cameras or drones.

Harmonic sound

A harmonic sound is a sound that has a frequency that is an integer multiple of the fundamental frequency of a sound. For example, if the fundamental frequency of a sound is 100 Hz, then frequencies of 200 Hz, 300 Hz, 400 Hz, etc. would be harmonics of this sound.
Harmonic sounds are often produced by sound sources that vibrate regularly, such as the strings of a violin or the vocal cords of a singer. They are also produced by synthetic sound sources, such as electronic keyboards and sound synthesis software.
It is relatively easy to recognize a harmonic sound. They generally have a clearer, more crystalline sound quality than non-harmonic sounds, and they can often be perceived as being more "pure" or "pleasant" to the ear.

Inelastic collision

An inelastic collision is a type of collision in which the two colliding bodies do not deform elastically and lose their initial kinetic energy. This means that the two bodies do not bounce against each other and part of their kinetic energy is converted into impact energy and dissipated into the environment.
When a car hits a wall, the kinetic energy of the car is converted into impact energy and dissipated into the environment as the car deforms and the wall absorbs energy. The car stops and does not bounce during this impact, indicating that the impact is inelastic.
The formula for kinetic energy before and after an inelastic collision can be written as follows:
Kinetic energy before > Kinetic energy after
Where ""Kinetic energy before"" is the kinetic energy of the two bodies before the impact, and ""Kinetic energy after"" is the kinetic energy of the two bodies after the impact.
It is important to note that in an inelastic shock, the kinetic energy is not conserved, but some of this energy is converted into shock energy and dissipated into the environment. Potential energy and elastic energy can also be converted into each other in an inelastic collision.

Inelastic shock

An inelastic collision is a type of collision in which the two colliding bodies do not deform elastically and lose their initial kinetic energy. This means that the two bodies do not bounce against each other and part of their kinetic energy is converted into impact energy and dissipated into the environment. When a car hits a wall, the kinetic energy of the car is converted into impact energy and dissipated into the environment as the car deforms and the wall absorbs energy. The car stops and does not bounce during this impact, indicating that the impact is inelastic. The formula for kinetic energy before and after an inelastic collision can be written as: Kinetic energy before > Kinetic energy after Where Kinetic energy before is the kinetic energy of the two bodies before the collision, and Kinetic energy after is the kinetic energy of the two bodies after the impact. It is important to note that in an inelastic shock, the kinetic energy is not conserved, but some of this energy is converted into shock energy and dissipated into the environment. Potential energy and elastic energy can also be converted into each other in an inelastic collision.

Kinematic equations

Kinematics is a branch of physics that involves describing the motion of an object or a system using measurable quantities like position, velocity, and acceleration. Unlike dynamics, which considers the forces causing the motion, kinematics is solely concerned with the description of motion and its properties.
The kinematic formulas are a set of equations that describe the motion of an object in terms of its position, velocity, and acceleration. There are several different kinematic formulas, but some of the most commonly used ones are:
Displacement (Δx): Δx = xf - xi
where xf is the final position and xi is the initial position of the object.
Average velocity (v): v = Δx/Δt
where Δt is the time interval over which the displacement occurs.
Acceleration (a): a = (vf - vi)/Δt
where vf is the final velocity and vi is the initial velocity of the object.
Final velocity (vf): vf = vi + at
where vi is the initial velocity, a is the acceleration, and t is the time interval.
Time (t): t = Δx/vi
where vi is the initial velocity and Δx is the displacement of the object.
Final velocity squared (vf^2): vf^2 = vi^2 + 2aΔx
where vi is the initial velocity, a is the acceleration, and Δx is the displacement of the object.
These formulas can be used to calculate various quantities related to the motion of an object, such as its position, velocity, acceleration, and time taken to travel a certain distance.
Motion graphs are graphical representations of the kinematic equations that depict the motion of an object in a more visual way. There are two main types of motion graphs: time-distance graphs and velocity-time graphs.
Time-distance graphs show the position of an object over time, with time on the x-axis and displacement on the y-axis. The slope of the graph represents the velocity of the object. A steeper slope indicates a higher velocity, while a flatter slope indicates a lower velocity.
Velocity-time graphs show the velocity of an object over time, with time on the x-axis and velocity on the y-axis. The slope of the graph represents the acceleration of the object. A steeper slope indicates a higher acceleration, while a flatter slope indicates a lower acceleration.
Trajectory analysis is the study of the path taken by an object as it moves through space. This analysis is important in many fields, including physics, engineering, and sports.
For example, in sports such as basketball, trajectory analysis is used to predict the path that a ball will take as it is thrown towards the basket. This analysis helps players to determine the best angle and velocity at which to throw the ball to increase the chances of it going through the hoop.

Kinematics

Kinematics is a method used in physics to describe the movements of an object or a system using quantities such as position, velocity and acceleration. It does not consider the forces that cause the motion, but focuses only on describing it and it's dynamics.
Kinematics is used to study different types of motion, such as parabolic motion, uniform rectilinear motion, and circular motion. Laws of motion are expressed using vectors and projections to describe the trajectory of an object, or body, in spacetime.
A kinematic analysis can be performed using a video or a chronophotograph. It can be used in many fields, such as mechanics, robotics, aerodynamics, ballistics, and also to study the movement of athletes to improve their performance.

Kinetic Energy

Kinetic energy is the energy possessed by a moving object. It is directly related to its speed and mass, and can be calculated using the following formula:
Kinetic energy = 1/2 * mass * velocity^2
The heavier an object is and the faster it moves, the more kinetic energy it has.
An example of kinetic energy is the movement of a soccer ball kicked by a player. When the ball is kicked, it acquires kinetic energy due to the force exerted by the player's foot, which gives it high speed. The higher the speed of the ball, the more kinetic energy it has.

Kinetic energy

Kinetic energy is the energy possessed by a moving object. It is directly related to its speed and mass, and can be calculated using the following formula: Kinetic energy = 1/2 * mass * speed^2 The heavier an object is and the faster it moves, the more d 'kinetic energy. An example of kinetic energy is the movement of a soccer ball kicked by a player. When the ball is kicked, it acquires kinetic energy due to the force exerted by the player's foot, which gives it high speed. The higher the speed of the ball, the more kinetic energy it has.

Law of conservation of energy

The law of conservation of energy is a fundamental principle of physics which states that energy cannot be created or destroyed, only converted from one form to another or moved from one place to another. This means that the total energy of an isolated system remains constant over time.
When an object falls from a height, it acquires kinetic energy as it falls due to the force of gravity, on the other hand the potential energy related to its position decreases. The object's total energy remains constant, however, because the kinetic energy gained during the fall equals the potential energy lost.
When a car travels on a road, the energy in its tank in the form of fuel is converted into kinetic energy which drives the car forward and into the frictional energy of the air on the car. When the car brakes and stops, this kinetic energy is converted into heat, which is dissipated into the environment. The total energy of the car remains constant, however, because the energy produced by the fuel used to move the car is equal to the heat energy lost when stopping and air friction during travel.

Law of gravity

The law of gravitation is a physical law that describes the gravitational attraction between two bodies. It states that all bodies in the universe are attracted to each other with a force proportional to their mass and inversely proportional to the square of the distance between them. The law of gravity was discovered by English scientist Isaac Newton in the 17th century. He also developed the mathematical formula that describes it: F = G * (m1 * m2) / d² where F is the gravitational force (in newtons), G is the gravitational constant (6.67 × 10^-11 N. m²/kg²), m1 and m2 are the masses of the two bodies (in kg) and d is the distance between them (in meters). An example of this law is the gravitational attraction between the Earth and the Moon. The gravitational force between these two bodies can be calculated using the above formula. If the mass of the Earth is 5.97 × 10^24 kg and that of the Moon is 7.35 × 10^22 kg, and if the average distance between these two bodies is 3.84 × 10^8 meters, then the gravitational force between them is: F = 6.67 × 10^-11 * (5.97 × 10^24 * 7.35 × 10^22) / (3.84 × 10^8)² = 1.23 × 10^20 N According to Albert Einstein's theory of general relativity, gravitation is not a force that attracts bodies towards each other, but rather a curvature of space-time caused by the presence of mass or energy. When a massive body, such as a planet or a star, is present in the universe, it digs a kind of hole in space-time due to its mass. The other bodies which are near this hole, like satellites or objects in free fall, are attracted towards it by following the curve of space-time. This is what creates the gravitation effect. Einstein developed an equation to describe this curvature of spacetime, known as the equation of general relativity. This equation predicts with great precision many phenomena observed in the universe, such as the deflection of light by the Sun and the precession of the perihelions of the planets of the solar system. The theory of general relativity is one of the most important and successful theories in modern physics.

Magnetometer

magnetometer is a device used to measure magnetic fields. There are several types of magnetometers, each with different characteristics and uses. Smartphones use Hall effect magnetometers, which measure the deflection of an electric current passing through a plate in the presence of a magnetic field. The stronger the magnetic field, the more current is deflected. Common magnetometer uses include: - land and sea navigation using the earth's magnetic fields to determine direction - geological surveys to measure magnetic fields associated with rocks and minerals - analysis of magnetic properties of materials for industrial applications such as electric motors, permanent magnets and data storage devices - scientific research to study magnetic phenomena in the natural environment, such as the aurora borealis and solar storms.

Mechanical energy

Mechanical energy is a quantity used in physics to designate the energy of a system stored in the form of kinetic energy and potential energy. Mechanical energy represents the sum of all energies existing in a system. In a case where the system encounters no frictional force, the law of conservation of energy applies: energy will neither be created nor destroyed. However, it could be transferred from one object to another or transformed into other types of energy.

Micro:bit

Micro:bit is a programmable handheld computer developed by a British non-profit organization called the Micro:bit Educational Foundation, in collaboration with businesses and government organizations. It was launched in 2015 with the goal of providing students with an affordable and accessible way to learn computer programming and electronics. The Micro:bit is a small computer that measures approximately 4cm x 5cm and weighs less than 50g. It has a processor, a memory, digital and analog inputs/outputs, an accelerometer, a compass, an LED matrix, a button and a socket for a battery. It can be programmed using an online integrated development software (IDE) or through a computer using different programming languages such as Python, JavaScript and Microsoft Block. It is designed for use in a learning environment, but can also be used for many creative and personal projects. It is used in many fields such as robotics, home automation, games, art projects, science projects and Internet of Things projects. Micro:bit Educational Foundation was created in 2013, this foundation aims to give children and young people access to education in programming and information technology. In 2015, they put out a tender for an affordable handheld computer for schools, which gave rise to the Micro:bit. Since its launch, it has been distributed to over 10 million students worldwide.

Niels Bohr

By Murray Gell-Mann (The Quark and the Jaguar) I received a call from a colleague about a student. He felt he had to give him a zero on a physics question, whereas the student demanded a 20. The teacher and the student agreed to choose an impartial arbiter and I was chosen. I read the exam question: Show how it is possible to determine the height of a building using a barometer. The student replied: You take the barometer from the top of the building, attach a rope to it, drag it down to the ground, then pull it up and measure the length of the rope. The length of the rope gives the height of the building. The student was right since he had answered the question correctly and completely. On the other hand, I could not give him his points: in this case, he would have graduated in physics when he had not shown me any knowledge of physics. I offered to give the student another chance. saying giving him six minutes to answer the question with the caveat that for the answer he had to use his knowledge of physics. After five minutes, he still hadn't written anything. I asked him if he wanted to give up but he replied that he had many answers for this problem and was looking for the best one. I apologized for interrupting him and asked him to continue. In the minute that followed, he hastened to answer me: — We place the barometer at the height of the roof. It is dropped by measuring its fall time with a stopwatch. Then using the formula x = 1/2*g*t*t, we find the height of the building. At that moment, I asked my colleague if he wanted to give up. He replied in the affirmative and gave the student almost 20. As I left his office, I called the student back as he said he had several solutions to this problem. 'Well,' he said, 'there are several ways to calculate the height of a building with a barometer. For example, it is placed outside when it is sunny. We measure the height of the barometer, the length of its shadow and the length of the shadow of the building. Then, with a simple calculation of proportion, we find the height of the building. - Good, I replied, and the others. — There is a fairly basic method that you will appreciate. We go up the floors with a barometer and at the same time we mark the length of the barometer on the wall. By counting the number of lines, we have the height of the building in barometer length. It is a very direct method. Of course, if you want a more sophisticated method, you can hang the barometer from a rope, swing it like a pendulum, and determine the value of g at street level and at roof level. From the difference in g the height of the building can be calculated. In the same way, we attach it to a large rope and while being on the roof, we let it descend to about street level. It is made to swing like a pendulum and the height of the building is calculated from the period of the oscillations. Finally, he concludes: — There are still other ways to solve this problem. Probably the best is to go to the basement, knock on the concierge's door and say, I've got a great barometer for you if you tell me how tall the building is. I then asked the student if he knew the answer I was looking for. He admitted he was, but he was fed up with college and professors trying to teach him how to think. »

Pedometer

pedometer is a device used to measure the number of steps taken during a walk or run. It's usually worn on the body, often attached to a belt or wristband, and uses sensors to detect movement and vibration that occurs when you walk or run. The data is then converted to steps. The history of pedometers dates back centuries, where people used step counters to measure the distance traveled while traveling on foot. The first modern electronic pedometers were developed in the 1960s, and were used primarily for scientific studies of physical activity. With the advent of information technology, pedometers have become more accessible and easier to use for the general public, and have been integrated into electronic devices such as cell phones, smart watches and activity bracelets. . A common example of using a pedometer is to track physical activity, users can set daily goals in terms of step count, and use this data to assess their fitness and improve their overall health. It can also be used in combination with other data, such as distance traveled and calories burned to track the progress of a fitness program. Pedometers can also be used for health research, population data analysis, and to develop health improvement programs.

Pi (in physics)

Pi (π) is a mathematical constant defining the ratio between a circle's circumference and its diameter. In other words, if you divide a circle's circumference by its diameter, you always get the same number, which is approximately equal to 3.14159.
Pi is an irrational number, meaning it has an infinite sequence of non-repeating decimals and cannot be expressed exactly as a fraction.
Pi (π) is present in numerous physics formulas, due to its relationship with circles, waves, and oscillations. Here are some examples of Pi's use in physics formulas:
Circular kinematics: For uniform circular motion, the angular velocity (ω) is defined as ω = 2πf, where f is the frequency. The linear velocity (v) is given by v = ωR, where R is the circle's radius.
Area and volume: The formulas for calculating the area of a disk (A = πR²) and the volume of a cylinder (V = πR²h), a sphere (V = 4/3πR³), or a cone (V = 1/3πR²h) all involve Pi.
Biot-Savart law: This law describes the magnetic field created by an electric current. In the case of an infinitely long and straight wire, the magnetic field at a distance R from the wire is B = (μ₀I)/(2πR), where μ₀ is the magnetic permeability of the vacuum and I is the current intensity.
Orbital period: The period (T) of an object in circular orbit around a central mass (M) is given by T = 2π√(a³/G(M+m)), where a is the average distance between the two objects (the semi-major axis of the orbit), G is the universal gravitational constant, and m is the mass of the orbiting object. This formula is derived from Kepler's third law and is valid for circular and elliptical orbits.
Harmonic oscillator formulas: In the case of a simple harmonic oscillator, such as a spring or a pendulum, the period (T) is defined by T = 2π√(m/k) for a spring and T = 2π√(l/g) for a pendulum, where m is the mass, k is the spring constant, l is the pendulum length, and g is the acceleration due to gravity.
Coulomb's law: The electrostatic force (F) between two point charges (q₁ and q₂) is given by F = (kq₁q₂)/r², where r is the distance between the charges and k = 1/(4πε₀), with ε₀ being the electric permittivity of the vacuum.
Heisenberg formula: Heisenberg's uncertainty principle states that it is impossible to know both the position (Δx) and the momentum (Δp) of a particle with infinite precision simultaneously. The uncertainty relation is given by ΔxΔp ≥ ħ/2, where ħ = h/(2π) is the reduced Planck constant.

Sound frequency

The frequency of a sound is the measurement of the number of cycles per second of a sound wave. When a sound source produces sound, it creates vibrations in the air (or any other medium) that propagate as sound waves. The frequency of a sound is the number of complete cycles of these vibrations that occur in one second.
The higher the frequency, the higher the sound, and the lower the frequency, the lower the sound. Frequency is measured in Hertz (Hz), which is the unit of frequency measurement. One Hertz represents one vibration per second. For example, a frequency of 1000 Hz corresponds to 1000 vibrations per second.
The first research concerning sound phenomena dates from the 6th century BC with the Pythagorean school which studied the functioning of vibrating strings and built a musical scale. The description of the first absolute determination of the frequency of a pure audible sound proposed by Mersenne in his Universal Harmony (1637). Mersenne also made the first calculations of the speed of sound. It was the German physicist and mathematician Christian Johann Doppler who was the first to suggest that the frequency of a sound could be modified by the movement of the source or the observer. This led to the Doppler effect, which bears his name and is now widely used in many applications, including meteorology and medicine. Physicist Lord Rayleigh developed the theory that now bears his name, known as Rayleigh's theory. This theory describes how sound waves propagate in a medium and how they are affected by different factors such as density and air pressure.

Sound intensity

Loudness is a measure of the acoustic energy of a sound. The higher the sound intensity, the louder the sound. The sound intensity is noted I and is expressed in watts per square meter (Wm-2). The sound intensity depends on several parameters: 1. the sound intensity at the transmitter 2. the distance from the receiver to the sound source 3. the presence of obstacles which absorb or reflect the sound waves We can measure the sound intensity with a sound level meter, like the FizziQ app, a device that converts sound energy into a measurable electrical signal.

Speed of sound

The speed of sound is the speed at which sound waves travel through a given medium.
Unlike the speed of light, the speed of sound is not a universal constant, but depends on several factors, such as temperature, pressure and medium. In air, sound waves travel faster as the temperature rises. They also move faster in denser liquids than in air or solids.
For example, the speed of sound in air at 20 degrees Celsius is 343 meters per second, the speed of sound in water is 5 times faster at around 1,480 meters per second, while in concrete it reaches the speed of 3,100 meters per second. Other characteristics of the medium, such as compressibility, can also affect the speed of sound.

Theodolite

theodolite is a measuring instrument used to measure horizontal and vertical angles. It is mainly used in surveying, civil engineering, construction and geodesy to measure angles of inclination and horizontal and vertical distances. It can also be used to measure the orientation of points of interest such as buildings, trees and monuments. Modern theodolites are usually equipped with electronic features such as electronic sensors and self-leveling devices to improve measurement accuracy. The theodolite of the FizziQ application allows to measure angles on the vertical plane compared to the horizontal, and also to measure the angle of a point aimed with the camera and the north. This tool is used to perform triangulation and height measurements.

Timbre (of a musical instrument)

The timbre of a musical instrument is the distinctive quality of its sound, which sets it apart from other instruments. This includes characteristics such as pitch, intensity, duration and spectrum (the frequencies that make up sound). For example, the timbre of a violin is different from the timbre of a saxophone, even though they play the same note at the same pitch.
The timbre of an instrument is influenced by many factors, such as the shape and size of the instrument, the materials used to make it, the way it is played (for example, with or without vibrato), and the effects sound used (for example, reverb or distortion). The timbre of an instrument can also change depending on the pitch of the note played, and some instruments have timbres that are more characteristic than others (for example, the deep, round sound of the tuba is easily recognizable).

Triangulation

Triangulation is a method used to determine the position of an object or point in space using measurements of distance or angles from two or more known reference points. There are several triangulation techniques, the most used is the method of triangulation from angular measurements which consists in determining the position of an object by using measurements of angles formed by lines connecting the object to two or more known reference points. In navigation, triangulation is used to determine the position of a ship or aircraft using distance measurements from coastal lighthouses or satellites. In topography, it is used to determine the altitudes and coordinates of points on the earth's surface. In cartography, it is used to create accurate maps of the earth's surface. In telecommunications, it is used to determine the position of a mobile phone or communication equipment using distance measurements from transmission towers. In geodesy, it is used to determine the precise coordinates of points on the earth's surface. In robotics, it is used to determine the position of a robot relative to its reference points.

Uniformly Accelerated Rectilinear Motion (MRUA)

Uniformly accelerated rectilinear motion (MRUA) is the motion of a mobile in a straight line whose acceleration is constant. In an MRUA, since the acceleration is constant, the change in speed is the same every second. On the other hand, the variation in position is therefore increasingly large, since a greater distance is traveled at each time interval. The use of the term rectilinear in the definition of the MRUA refers to movement in a straight line. When a movement takes place in more than one axis (for example in a projectile movement), the decomposition of this movement according to the different axes facilitates its analysis.

White noise

White noise is a type of noise that has a constant loudness across all frequencies. This means that white noise is made up of all audible frequencies equally. One can imagine white noise as being similar to a wall of sound, where every frequency is represented equally. White noise is used as a reference to measure the quality of information transmission in electronic and electrical communications, as well as to measure the absorption of materials and the reflection of surfaces in acoustics and physics.

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