The displacement of an object is the distance travelled in a particular direction from a starting point.

A vector is a quantity with magnitude (size) and direction. Displacement and velocity are both vector quantities.

The velocity of an object is its speed in a particular direction.

Displacement and velocity as vectors (v=s/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

the distance travelled in a straight line from a starting point

a quantity with a magnitude (size) and a direction

a quantity with a magnitude (size) but not a direction

the speed of an object in a particular direction

Match the key words or phrases to their definitions.

Which of these are examples of displacements?

A train takes 2 hours to travel from one station to another which is 150 km west of the starting point.
Calculate the velocity of the train.

A pupil walks 5 m north, 3 m south and then 2 m north.
Which of these statements about the pupil's journey are correct?

Two cars are approaching each other. Car A has a velocity of 4 m/s west and Car B has a velocity of 4 m/s east. 
What is the relative velocity (speed) of the two cars?

A pupil walks 10 m west in 10 s, 5 m east in 5 s and 15 m west in 25 s.
Calculate the magnitude of the average velocity for the complete journey (do not give the direction).

A pupil measures the time taken for different sports balls to travel 30 cm.
Use the times to put the balls in order of decreasing speed, starting with the fastest.   

average speed = distance travelled ÷ time taken

average speed = distance travelled × time taken

distance travelled = average speed × time taken

time taken = distance travelled ÷ average speed

Which three of these equations show the correct relationship between average speed, distance travelled and time taken?

Change the value of the anomalous result to match the others in the set.

Repeat the test for the anomalous result and replace it with the new value.

Repeat the whole experiment from the start using different equipment.

Cross out the anomalous result and ignore it in any calculations.

Use the anomalous result in any calculations but not on the graph.

What should be done with a single anomalous result in a set of five readings?

A pupil measures the time it takes for a car to pass between two street lamps as 5.0 s. 
If the car is moving at 8.0 m/s, how far apart are the lamps?

A quantity that has a magnitude but not a direction.

A quantity that has a magnitude and a direction.

A quantity that always has a value of zero.

Which of these is a correct definition of a scalar quantity?

The average speed of the ball was 10 m/s.

The instantaneous speed of the ball was the same throughout the fall.

The highest instantaneous speed of the ball was 10 m/s

The highest instantaneous speed of the ball was less than 10 m/s

The highest instantaneous speed of the ball was greater than 10 m/s

A tennis ball was released from a height of 20 m and took 20 s to fall to the ground.
Which statements about the speed of the ball are correct?

This lesson will soon be taken down.

Displacement and velocity as vectors (v=s/t)

Lesson outcome