Speed SA - CCEA

Part of Combined ScienceRoad transport and safety

What are the key learning points about speed?

  • How to calculate speed.

  • State a unit for speed.

Back to top

What is the definition of speed?

Speed is defined as:

The distance travelled in 1 second.

It is measured in m/s or km/h (or mph in UK cars).

Equation triangle for calculating speed

Speed can be calculated using:

Average speed = \(\frac{distance}{time}\)

Speed, or distance, or time can be calculated using the dst triangle.

Cover the letter you want to find to get the formula you need.

distance = speed x timed = s x t
speed = \(\frac{distance}{time}\)speed = d ÷ t
time = \(\frac{distance}{speed}\)time = d ÷ s

If a ball has a speed of 5 m/s it means that it travels 5 m every second.

Worked example

If a car travels 24 m in 2 seconds, what is its speed?

Answer

Speed = \(\frac{distance}{time}\)

Distance = 24 m.

Time = 2 s.

Speed = \(\frac{24}{2}\)

Speed = 12 m/s.

The car has a speed of 12 m/s.

Question

Calculate the average speed of a hockey ball if it takes 3 seconds to travel 60 m across a hockey pitch?

Question

Find the distance travelled by Caitlyn if she sprints at an average speed of 9 m/s for 4 seconds?

Question

Find the time taken to cover 256 m at an average speed of 8 m/s?

Question

Find the speed of a train if it covers 2 km in 120 seconds.

Key points

  • Speed is the distance travelled in 1 second.
  • Speed = \(\frac{distance}{time}\)
  • Speed is measured in m/s or km/h.
  • If an object has a speed of 5 m/s it means that it travels 5 m every second.
Back to top

How much do you know about speed?

Back to top

More on Road transport and safety

Find out more by working through a topic