A displacement-time graph shows the displacement of an object over a period of time.

A velocity-time graph shows the velocity of an object over a period of time.

The acceleration of an object is the rate of change of velocity. This is how much the velocity changes per second.

Deceleration is used to describe a change in velocity where the object slows down.

Calculating from velocity-time graphs (a=(v-u)/t)

Combined science

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

this shows the displacement of an object over a period of time

this shows the velocity of an object over a period of time

used to describe an object which is slowing down

Match the key words and phrases to their explanations.

Find the change in velocity between 0 s and 8 s shown in this graph.

When is the magnitude (size) of the acceleration greatest according to the velocity-time graph?

The graph shows an electric car with changing velocity.
At which of these times is the acceleration greatest?

The velocity-time graph shows the movement of a robotic arm in a factory.
Calculate the velocity of the arm in m/s between 0 s and 20 s. 
You do not need to include the units in your answer.

A car starts from rest and accelerates at a constant 3.5 m/s$$^2$$.
Calculate its velocity after 6.0 s.

Five yachts have a sailing race around the same course. Their completion times are shown.
Starting with the fastest, put them in order of average speed.

Which word is used to describe an object which has a decreasing velocity?

An electric scooter has a maximum speed of 2.5 m/s.
Calculate the maximum distance it can travel in 50 s.

A satellite travels a distance of 10 800 km in 1 hour. What is the speed of the satellite in km/s?

Which of these is the correct unit for acceleration?

A train speeds up from 2.0 m/s to 8.0 m/s in a time of 50 s.
Calculate the acceleration of the train.

This lesson will soon be taken down.

Calculating from velocity-time graphs (a=(v-u)/t)

Lesson outcome