Motion Graphs

What information can I get from a motion graphs?

Starter: Quick Quiz – prepare to answer some questions.

QUESTION REVEALWill you get an easy or a hard one?10 seconds to answer:

State a unit for speed. If I run 200m in 20

seconds, what is my speed?

What is the resultant force?

Name 2 contact forces.

What is the equation for speed?

Name an “action at a distance” force.

What is the unit for weight?

Name 2 horizontal forces.

What as the difference between average speed and instantaneous speed?

1 3

4 5 6

7 8 9

2

Learning Outcomes

• explore representing motion as a distance–time graph

• explore representing motion as a speed–time graph and H: a velocity–time graph

• explain the difference between speed and velocity

• H: explain the difference between displacement and distance

What does this graph show? Discuss!!!

This graph shows distance or displacement over time.

What is the difference?!

A “distance-time” graph

Distance time graphsAt A the speed is constant.

At B the object has stopped

At C the object is moving again, at a constant rate, but quicker than before.

Tasks:

1) Complete the section on the summary sheet on distance –time graph

2) Complete the practise questions.

3) Make a revision card showing a DT graph and label it.

Using distance time graphs to work out your speed.

• Remember speed = distance/time

Speed (velocity) – Time Graphs

What does this graph show now ? Discuss!!!

Speed

What about this “velocity” thing?

Velocity-time graphsVelocity

(m/s)

Time (s)

1) Upwards line = acceleration

2) Horizontal line = constant speed

3) Steeper line = greater acceleration

4) Downward line = deceleration

The area under the line is equal to the distance travelled.

Tasks

1) Make a revision card for Velocity – Time graphs.

2) Complete the summary sheet for V-T graphs.

Practise the exam questions on Velocity – Time graphs

Extension task

• Write down your journey to school. Include every time you walk, stop at a shop, sit on the bus, walk into the building etc and how long.

• Use this to draw a distance – time graph . Annotate it.

• Work out your speed (velocity) at each stage.