1.1 Motion

Distance

how far an object moves along its path

Displacement

how far an object has travelled from its starting point

Distance

how far an object moves along its path

Displacement

how far an object has travelled from its starting point

Speed

the rate of change of distance

The equation linking average speed, distance travelled and time taken

Average speed = distance travelled ÷ time taken

The equation linking uniform average speed, initial speed and final speed

uniform average speed = (initial speed + final speed) ÷ 2

The equation linking acceleration, final speed, initial speed and time taken

acceleration = (final speed – initial speed) ÷ time taken

Unit for speed and velocity

Metres per second (m/s)

Unit for distance and displacement

Metres (m)

Unit for time

Seconds (s)

Unit for acceleration/ rate of change of speed

Metres per second squared (m/s²)

Why is average velocity 0

If start and finish are the same, total displacement is 0 so average velocity is also 0

Distance-time graph

A graph with distance on the y-axis and time on the x-axis

Horizontal line on a distance-time graph

Represents a stationary object

Inclined line on a distance-time graph

Represents an object moving at a constant speed

Curved line on a distance-time graph

Represents an object that is accelerating/ decelerating

How to calculate the speed of an object from a graph

Gradient of a distance-time graph

How to calculate the distance/ displacment from a graph

Area under graph

Velocity-time graph

Velocity on the y-axis and time on the x-axis

Horizontal line on a velocity-time graph

Represents an object moving at a constant speed

Inclined line on a velocity-time graph

Represents an object accelerating at a constant rate

How to calculate the acceleration of an object from graph

Gradient of a velocity-time graph

Velocity

The speed of an object in a particular direction

The equation linking average velocity, displacement and time

Average velocity = displacement ÷ time

The equation linking uniform average velocity, initial velocity and final velocity

Uniform average velocity = (initial velocity + final velocity) ÷ 2

Acceleration

The rate of change of velocity over a specific time

The equation linking acceleration, final velocity, initial velocity and time

Acceleration = (final velocity – initial velocity) ÷ time

Retardation

When an object is slowing down and its acceleration has a negative value