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Rogue Physicist.  Free resources for physics education © 2006-2016 Dorian Pascoe.  Email: dorian.pascoe@hotmail.co.uk

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...measuring speed...

 

 

 

Objectives:

 

  
 

 

 

Miles per hour.

Not the only unit of speed.

  

 

 

• Know that speed can be measured in lots of different units, and be able to state several examples.

 

 

• Be able to come up with simple ways of measuring or comparing speed.

 

 

• Be able to use data to calculate the speed of an object.

 

 

  

 

 

 

 

 

 

 

 

 

 

 

Task 1 - Starter

 

  
 

 

 

Looking good!

 

 

  

 

Discuss with the person next to you:

 

 

1) What units can we can use to measure speed?

 

You will probably know several!

 

 

 

2) What does speed mean?

 

Try to come up with a sentence, without using any of the following words:

 

 

fast           slow           quick         rapid

 

  

 

 

 

 

 

Units of speed.

 
 

 

 

 

Units of distance can be combined with units of time to make units of speed.  Your teacher will explain how.

  
 

 

Units of distance

 

Units of time

 

Units of speed

 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

    

 

 

 

 

 

 

 

 

Task 2 - Who is fastest?

 

  
 

 

 

Think hard!

 

  

 

Working in groups of three, you need to find out who can hop fastest - but only one person is allowed to hop at a time!

 

 

 

Decide on a simple method you could use to compare the speeds of the people in your group, so you can rank them from slowest to fastest.

 

 

 

You can use the following equipment:

 

     ▪ 20m tape measure

 

     ▪ stopclock

 

 

 

 

 

Write a simple outline of your method in your exercise book.  Explain clearly what you will do, and what you will measure.  Your teacher may ask some of you to share your ideas with the class.

 

  

 

 

 

 

 

 

 

 

 

Task 3 - Carry out your method

 

  
 

 

 

Measuring.  Yay!

 

 

  

 

Your teacher will take you outside, so you can carry out your method.

 

 

 

You only have 5 minutes to collect your data!  Make sure everyone in your group has recorded the results.

 

 

 

 

Extension: see if you can work out how far (in centimetres or metres) you travelled each second.  Write your answer in your exercise book, along with a calculation to show how you worked it out.

 

  

 

 

 

 

 

 

 

 

 

 

Task 4 - Calculating how fast you were moving

 

  
 

 

Think hard!

 

  

 

How can we work out your speed in metres per second?

 
 

 

• Try to work it out on your own, using a calculator.

 

 

• Your teacher will ask some of you to share your ideas with the class.

 

 

  

 

 

 

 

 

 

 

 

 

 

 

Task 5 - How fast are you moving right now?!

 

  
 

 

Think hard!

You may be moving faster than you think...

  

 

 

What speed are you moving right now, sat at your desk in the science laboratory?

 

 

 

 

Think about:

 

 

• ...the earth spinning...

 

• ...the earth orbiting the sun...

 

• ...the sun orbiting around the centre of the galaxy...!

 

 

 

 

 

Your teacher may explain the idea of Galilean reference frames.