Motion Graphs 2

Motion Graphs - Part II

Objectives

• Be able to plot distance-time graphs to show simple journeys for objects moving at constant speeds.

• Be able to interpret distance-time graphs in order to describe and explain the motion of the object.

• Be able to calculate the speed of an object by finding the gradient of a distance-time graph.

Task 1 - Starter Questions

Remind the person next to you:

• The units of speed.

• The units of acceleration.

• What each term means.

• How to find the speed of an object from a distance time graph.

Task 2

We are going to plot to show the position of Mr Pascoe as he goes on a short journey, and then analyse the information on the graph.

Note: this task is available as a word document here.

Task 3 - Qualitative Analysis

When you have finished, label these sections on your graph:

A – Leaves the house.

B – Walking towards the shop.

C – Stops to talk to a friend.

D – Continues walking with friend, more slowly.

E – Stops in the shop to buy the paper.

F – Rushes back when he realises the time!

Task 4 - Quantitative Analysis

Calculate gradients to find the following:

• The speed Mr Pascoe initially walks away from the house.

• The speed Mr Pascoe walks with his friend.

• The speed Mr Pascoe travels when returning home.

Remember - the formula for calculating gradients is:

gradient = increase in y ÷ increase in x

Now explain, in full sentences:

• What does the slope of the line tell you about the speed?

• What does the slope of the line tell you about the direction?

• How can you tell when the object is stationary?