Hi everyone, this is a quick glossary of 20 words that are really important to know and understand if you want to succeed in Pure and Applied Science in Cegep (school of higher studies in the province of Quebec with students around 17 to 20 years old). The words bellow are linked to the physics notion you will or have learned, it is important to keep in mind that outside of physics their meaning could change, thank you.
acceleration
noun
The rate of change of velocity with time, measured in m/s². Acceleration occurs whenever speed, direction, or both changes — a car speeding up, slowing down, or turning a corner at constant speed are all accelerating.
Example: The car's acceleration was instant as soon as the driver pressed the accelerator.
fr: accélération
amplitude
noun
The maximum displacement of a wave from its equilibrium (rest) position. For sound, larger amplitude means louder; for light, larger amplitude means brighter.
Example: The amplitude of the wave increases when more energy is added to the system.
fr: amplitude
center of gravity
noun
The single point where an object’s entire weight can be considered acting. For a uniform gravitational field it coincides with the centre of mass, and it determines whether an object tips over or stays balanced.
Example: The center of gravity of the object determines whether it will remain stable or tip over.
fr: centre de gravité
Doppler effect
noun
The change in observed frequency of a wave caused by relative motion between the source and observer, a rising pitch as an ambulance approaches, falling as it passes, or redshift in light from receding galaxies.
Example: We noticed the Doppler effect when the ambulance passed by and the pitch of the siren suddenly changed.
fr: effet Doppler
elastic collision
noun
A collision in which both momentum and kinetic energy are conserved — no energy is lost to heat, sound, or deformation. Collisions between hard billiard balls or gas molecules approximate this closely.
Example: During the experiment, the two carts separated cleanly after the elastic collision.
fr: collision élastique
energy
noun
The capacity to do work or cause change, existing in many interchangeable forms — kinetic, potential, thermal, electrical, chemical, nuclear. Total energy in an isolated system is always conserved.
Example: The moving car has enough energy to climb the hill without slowing down.
fr: Énergie
force
noun
In mechanics, any action that tends to maintain or alter the motion of a body or to distort it.
Example: The force of friction acted opposite to the motion of the block, reducing its acceleration on the surface.
fr: force
free fall
noun
Motion under gravity alone, with no other forces (like air resistance) acting. In free fall, every object accelerates at the same rate regardless of mass, roughly 9.8 m/s² near Earth’s surface.
Example: The ball entered free fall as soon as it left the student’s hand and began accelerating downward.
fr: chute libre
friction
noun
The force that resists relative motion between two surfaces in contact, acting opposite to the direction of motion (or attempted motion). Static friction prevents motion from starting; kinetic friction opposes motion already underway.
Example: The friction between the surfaces slowed down the motion of the block.
fr: friction
inelastic collision
noun
A collision in which momentum is conserved but kinetic energy is not — some energy converts to heat, sound, or permanent deformation. A perfectly inelastic collision is one where the objects stick together afterward.
Example: During an inelastic collision, some of the system’s kinetic energy is lost to heat or deformation.
fr: collision inélastique
inertia
noun
An object's tendency to resist changes in its state of motion — to keep doing whatever it's already doing unless acted on by a net force. Mass is the quantitative measure of inertia.
Example: Because of its inertia, the heavy cart resisted changes in its motion when the student pushed it.
fr: inertie
longitudinal wave
noun
A wave in which particles of the medium oscillates parallel to the direction of wave travel, creating alternating compression and rarefaction — sound waves are the classic example.
Example: Sound travels through air as a longitudinal wave, where the particles compress and expand in the same direction as the wave moves.
fr: onde longitudinale
mass
noun
A measure of the amount of matter in an object and its resistance to acceleration (inertia). Unlike weight, mass does not change with location — an object has the same mass on Earth, the Moon, or in deep space.
Example: The object’s mass made it harder to accelerate when the student applied a force.
fr: masse
power
noun
The rate at which work is done or energy is transferred, measured in watts (1 W = 1 J/s). The same amount of work done faster requires more power.
Example: The motor’s power was high enough to lift the load at a constant speed.
fr: puissance
speed
noun
The rate at which an object covers distance, a scalar quantity with magnitude only (no direction), distinct from velocity, which also specifies direction.
Example: The car’s speed increased steadily as the driver pressed the accelerator.
fr: vitesse
standing wave
noun
A vibration patterns that appear to stay in one place rather than traveling through a medium.
Example: A standing wave formed inside the guitar string when the musician plucked it, creating clear nodes and antinodes along its length.
fr: onde stationnaire
transverse wave
noun
A wave in which particles of the medium oscillates perpendicular to the direction of wave travel — light, water ripples, and waves on a rope are all transverse.
Example: On a rope, a transverse wave forms when the student moves one end up and down, creating peaks and troughs that travel along the cord.
fr: onde transversale
wave
noun
A disturbance that transfers energy from one place to another without transferring matter, characterized by amplitude, wavelength, frequency, and speed. Waves can be transverse or longitudinal, and mechanical (requiring a medium) or electromagnetic (not requiring one).
Example: An electromagnetic wave can travel through empty space because it does not require a physical medium.
fr: onde
weight
noun
The weight of an object is defined as the force of gravity on the object and may be calculated as the mass times the acceleration of gravity, w = mg. Since the weight is a force, its unit is the newton. For an object in free fall, so that gravity is the only force acting on it, then the expression for weight follows from Newton’s second law.
Example: The weight of the object increased as it was moved to a planet with stronger gravity.
fr: poids
work
noun
The energy transferred to or from an object by a force acting over a distance, W = Fd cos θ. Work is done only when a force causes displacement in the direction the force acts.
Example: The work done by the force on the object is 45 J.
