Chapter Graphic
: Wheel Race
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Approach: Team  Level: Year 8 only
Focus: Co–operatively plan, carry out and report on an experiment involving the effects of mass and rotational inertia on the acceleration of a wheel.
712k
Resources: 2 wheel cases, 8 washers, 2cm blutak, test track, cork, red pen, blue pen, large paper (for planning), stop watch, instruction card.

Questions / instructions:
I want you to imagine that you are a team of scientists who design wheels. You are to experiment and conduct tests with different kinds of wheels to find one that will gain speed most easily. You will need to think about the weight of the wheels. You also need to think about how you can arrange the washers inside the wheels. The washers act as weights. To help you with your work, you have two containers that can act as wheels, 8 washers that can be used as weights in the wheels, some blutak for joining and arranging washers in the wheels, a cork and a test track for checking the speed of the wheels that you design. A stop watch is also available if you want to use it.
Show students each of the supplies, but don't give them out yet.
So that everyone takes part in the reporting, I'm going to ask [name students 1 and 2] to report to me on what you did, later I'll ask [name students 3 and 4] to tell me your results and the best way to make a wheel that gains speed most easily. You can have a couple of minutes now to talk about what you will say in your explanations to me. This card describes the three things your team is asked to do.
Place the card for all students to see, then read it to the team.
Give the planning sheet and the blue pen to the students. Teacher withdraws, and allows students time to plan their explanations.
[Name students 1 and 2] I want you to tell me the plan of your experiment. The others can help with the explanations if that would be helpful.
Allow time.

a a a
% responses
y8
Planning:
a
a
to try different arrangements of washers
44
to achieve consistant set up and release of wheel on ramp
7
to achieve accurate measurement of speed/time
19
to check consistency by replication
4
to involve all students
56
Report on planning:
a
a
clear, accurate, full
9
reasonably clear, accurate
54
You have 10 minutes to work through your experiment. If you make changes, use the red pen to write these down on your planning sheet. After that I will ask you to report to me on what you did, to tell me your results, and to explain what is the best way to make a wheel that gains speed most easily. Use all of your time well, so that you get the best results.
Give students the equipment. Take in the blue pen and give students the red pen. Allow 10 minutes for the experiment.
[Name students 3 and 4]: I want you to tell me your results and to explain the best way to make a wheel that is fast at picking up speed. The others can help with the explanations if that would be helpful.
a
a Experimentation:
a
a
tried several different arrangements of washers systematically
31
set up and released wheel consisently
25
measured speed/time carefully
25
included replication of most/all trials
22
high participation
60
Report on experiments:
a
a
clear, accurate, full
2
reasonably clear and accurate
24
Commentary:
The apparatus for this task was not easy to use, which perhaps accounts for the modest proportions of teams who achieved high standards in the different aspects of experimentation. Important aspects were often not considered in the planning.
 
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