Kinematics

Distance

Symbol: d

Unit: m

scalar quantity

• refers to how much ground an object has covered during its motion

Displacement

Symbol: s

vector quantity

• Describes the straight line distance between two points in a given direction

Speed

Symbol: S

Unit: ms^-1

Scalar quantity

• how fast an object is moving

• the rate at which an object travels in a given distance in a particular time

Velocity

Symbol: v

Unit: ms^-1

Vector quantity

• the rate of change of displacement in a particular time / speed in a given direction

Acceleration

Symbol: a

Unit: ms^-2

Vector quantity

• the rate of change in velocity over a given time

Equation for acceleration

Change in velocity / change in time

Draw distance speed time triangle

Describe what is happening at each point of this displacement time graph

A - steady increase in displacement with a constant velocity (object is moving away from starting point)

B - stationary, displacement is constant

C - steady decrease in displacement with a constant velocity (object is returning to the start point)

The gradient of this graph shows the velocity

V-t graph

What are Newton’s 3 laws of motion

1. Law of Inertia - An object at rest stays at rest, and an object in motion stays in motion at a constant velocity, unless acted upon by an unbalanced force

2. The rate of change of momentum is directly proportional to the force applied in the direction of force

3. For every action, there is an equal and opposite reaction