4
Education
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(b) Discover if your predictions were
correct by rebuilding your models
with two gears that are different
in size using these images.
(c) Think of a way to compare the speed that the fan turns, with the speed of the
crank when the big gear is attached to the crank and the small gear is attached
to the fan blades.
(d) How easy/hard is it to turn the crank with this arrangement compared to when
the gears were the same size?
• Make a note of your responses in your notebook.
(e) Compare the speed at which the fan turns with the speed of the crank, when the
small gear is attached to the crank axle and the big gear is attached to the fan
blade’s axle.
(f) How easy/hard is it to turn the crank with this arrangement, compared to when
the gears were (i) the same size and (ii) the large gear was the driver?
• Make a note of your responses in your notebook.
9. (a) Discuss your observations of gear systems using different sized gears.
(b) Do your observations support the prediction that you wrote earlier? Report your
conclusions using evidence from your investigations.
