The average speed of an object is the distance it travels each second (m/s). It is a scalar quantity.

The instantaneous speed of an object is the speed at a particular moment.

Some quantities only have magnitude (size), and not direction. This includes distance and speed.

A scalar quantity only has magnitude (size).

The relative speed of objects is the difference in their speeds taking into account direction of movement.

Different speeds (v=s/t)

Physics

In the Energy of moving objects unit, they will build on this knowledge to learn how to calculate the amount of energy of objects have because they are moving, stretched or in a gravitational field; and to calculate energy transfers using knowledge of energy conservation and dissipation.

In the Moving by force unit, pupils learnt how to calculate speed and describe motion using distance-time graphs, apply Newton’s First Law of motion and calculate the amount of energy needed to move an object to a new position.

Measuring and calculating motion

Subjects which particular individuals may be sensitive to, eg, adoption, migration, bereavement or death, divorce.

Depiction or discussion of sensitive content

the average distance travelled every second

the speed of an object at a particular moment of time

a quantity that has only magnitude (not direction)

the speed of one object compared to the speed of another object

Match the key words or phrases to their definitions.

Match the activity to the typical speed for that activity.

A skateboarder travels a distance of 400 m in 50 s. 
What is their average speed?

Sound waves travel at 330 m/s in air. A boy sees a firework explode in the distance. The sound arrives 6.0 s after the flash. 
How far away from the boy did the firework explode (to 2 s.f.)?

Two cars are traveling in opposite directions (towards each other). The first car is travelling at 30 km/h and the second is travelling at 70 km/h.
What is the relative speed of the cars?

During a race, cyclist A is traveling at 10 m/s and is 200 m behind cyclist B, who is travelling at 8 m/s in the same direction. 
How long will it take cyclist A to catch up with cyclist B?

Members of a running group compared their times to complete a park run. 
Use the times to put the runners in order of decreasing speed, starting with the fastest.   

Which of the following is not a valid unit for speed?

cyclist A has travelled 20 metres in 3 seconds

Two cyclists are racing up a hill. Cyclist A has a speed of 20 m/s and cyclist B travels 48 metres in 3 seconds. 
If the cyclists continue to travel at these same speeds, which statement is correct?

Which of these distance–time graphs shows the motion of a stationary object?

The motion of two cars, A and B, has been displayed on a distance–time graph. 
Which statement about the two cars is correct?

Content guidance

Depiction or discussion of sensitive content

Adult supervision recommended

Starter Quiz