IB Physics Topic 1 Definitions
This page contains our IB Physics definitions for topic 1. By learning each one of these definitions, you will fully cover the content for IB Physics 'Space, Time & Motion'.
acceleration
It is the velocity travelled per unit time or displacement travelled per square unit time
air resistance
The friction air exerts on an object's motion through it
Angular Deviation
The angle at which the axes of one frame of reference deviate from another in a spacetime diagram
Angular Impulse
The change in angular momentum due to the application of an external torque over an extended time
Angular Momentum
The momentum of rotational motion, calculated as the moment of the linear momentum around the axis of rotation
Angular velocity
It is the angle travelled per unit time
average speed
The speed averaged over the total distance travelled
Centripetal acceleration
It is the acceleration of an object towards the center of the circle during uniform circular motion
Centripetal force
It is the force that causes centripetal acceleration
chemical energy
It is the energy stored in the bonds of molecules
displacement
It is the net distance an object has travelled from its starting point in a direction
distance
It is the amount of space travelled
drag force
The force fluid resistance exerts on an object
dynamic friction
The force exerted to stop a moving surface from moving
efficiency
It is the ratio of useful energy output to the total energy input
elastic potential energy
It is the energy an object holds when it is compressed or tensed
electrical energy
It is the energy produced by the flow of charged particles
electrostatic force
The force between two electrically charged objects
energy
The ability to move a unit force a unit distance, measured in joules. ie the amount of work done
Energy density
It is the energy released per unit volume of fuel
equilibrium
The state of all forces on an object being balanced and cancelling out to zero
fluid resistance
The friction a fluid exerts on an object's motion through it
free fall
It is when an object falls in the absence of air resistance
friction force
The force a surface parallely exerts to counteract another surface's motion
Fuel
It is energy extracted from source to power devices
gravitational force
It is the attractive force exerted by an object's mass on another object
gravitational potential energy
It is the energy an object holds by being above a surface
impulse
It is the change of momentum
instantaneous speed
The speed at a particular point in time
Invariant Quantities
Quantities that remain constant and do not vary between observers, including spacetime interval, proper time interval, proper length, and rest mass
kinetic energy
It is the energy of movement
Length Contraction
The phenomenon where objects appear shorter in the direction of motion when moving at high velocities relative to a stationary observer
Light Clock
A conceptual device used to illustrate time dilation, where the time taken for light to bounce between mirrors increases with the clock's velocity
magnetic force
The force between two magnetic objects
momentum
It is the product of mass and velocity
motion
It is the movement of an object
nuclear energy
It is the energy produced by the nuclear decomposition of an atom
Period
It is the time required to complete one rotation
power
It is the rate of energy transfer or rate of work done
projectile motion
It is when an object is launched into the air in a parabolic path
reaction force
The force a surface perpendicularly exerts on an object due to its weight
relative velocity
It is an object's velocity from a frame of reference
Rotational Equilibrium
A state where there is no resultant torque acting on an object, meaning it has no angular acceleration
Simultaneity
The concept that the simultaneity of events depends on the observer's frame of reference, meaning events that are simultaneous in one frame may not be in another
sound energy
It is the energy of sound waves
Specific energy
It is the energy released per unit mass of fuel
speed
It is the distance travelled per unit time
static friction
The force exerted to stop another resting surface from moving
tension force
The force a spring, rope, or cable exerts along its length in both directions to another object
thermal energy
It is the energy of heat an object holds
Time Dilation
The phenomenon where time appears to move slower for objects moving at higher velocities relative to a stationary observer
Torque
The turning effect of a force around a given axis, calculated as the product of the force and the perpendicular distance from the axis of rotation to the line of action of the force
Translational Equilibrium
A state where there is no resultant force acting on an object, meaning it has no translational acceleration
Translational Motion
Motion in which all particles of an object move in parallel paths
Uniform circular motion
The motion of an object in a circle at a constant speed
velocity
It is the displacement per unit time
work
It is the measure of energy required to apply a force to move an object in the direction of the force
Next Up
You have completed the topic 1 definitions for IB Physics - continue with related resources below or explore the full IB Physics course from the IBO.
Other topic 1 resources