Speed, velocity and acceleration
Speed
Speed is a scalar quantity and is the rate of which an object covers a distance
Speed can be calculated using the equation:
Speed = distance/time

Speed  measured in meters per second (m/s)

Distance  measured in meters (m)

Time  measured in seconds (s)

Worked example:
A car travels 100 m in 10 s. Work out its average speed.

Speed = distance/time

Speed = 100/10

Speed = 10 m/s
Velocity
Unlike speed, velocity is a vector quantity, meaning it has a magnitude and direction.
Velocity is calculated by the change in distance divided by the time taken.
Velocity = d/t

Velocity  measured in meters per second (m/s)

distance moved measured in meters (m)

time taken  measured in seconds (s)
A () velocity means that the object is moving backwards and a (+) velocity means that it is moving forward.
Acceleration
Acceleration can be calculated by using the equation:
A=(VU)/T
Acceleration = change in velocity/time taken

Acceleration (A)  measured in meters per second (m/s)

Change in velocity (VU)  measured in (m/s)

Time taken (T)  measured in seconds (s)
For example, a lorry accelerates in 5 s from 25 m/s to 35 m/s. Its velocity changes by 35  25 = 10 m/s. This means the lorry's acceleration is 10 ÷ 5 = 2 m/s2