Velocity on displacement-time graphs (v=s/t) | Exit Quiz | Oak National Academy

Match the key word or phrase to the explanation.

• motion sensor

• a vector that gives speed and direction

• displacement–time graph

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

• displacement

• a vector which is the distance and direction from a point

• velocity

• measures the distance between an object and itself

Answer explanation

Displacement is a vector that gives the distance and direction from a point, velocity gives the speed and direction. Displacement-time graphs show the displacement over time and the displacement can be detected with a motion sensor.

Which feature of a displacement-time graph shows the velocity?

• the intercept on the displacement axis (y-axis)

• the intercept on the displacement time (x-axis)

• the area beneath the line

• the gradient of the line

• the maximum on the displacement axis

Answer explanation

Velocity is the rate of change of displacement (how much the displacement changes per second) and this is shown by the gradient.

The graph shows the motion of a box placed on a conveyor belt in a factory. Find the average velocity of the box.

• A (red)

• B (blue)

• C (black)

• D (green)

Answer explanation

Line C has the greatest gradient and so shows the highest velocity.

Select the options which describe the motion between 2 s and 4 s.

• negative displacement

• positive velocity

• negative velocity

• constant velocity

• changing velocity

Answer explanation

The object has a negative displacement and a constant negative velocity between those times.

A pupil has plotted a graph to show their movement as they run across the classroom. Why is this graph unrealistic?

• The change in their velocity is too sudden.

• Their velocity is too high for a human to run.

• The velocity is too low for running.

• It does not take into account the direction of travel.

• They have not given the graph a title.

Answer explanation

The graph shows an instant change in velocity and this is unrealistic.