In a bicycle, the pedals drive the chainwheel, which is connected by means of a chain to the cogwheel, a small wheel attached to the rear wheel. In a certain bicycle, the radius of the chainwheel is 12.0 cm, the radius of the cogwheel is 4.0 cm, and the radius of the rear wheel is 66.0 cm. At what rate should the cyclist be pedaling in order for the bicycle to have a forward speed of 10.0 m/s?
A) 48.2 rpm
B) 16.1 rpm
C) 12.1 rpm
D) 24.1 rpm
E) 60.3 rpm

Question

Quizplus · Accepted Answer

The correct answer is A because the chainwheel drives the cogwheel, which in turn drives the rear wheel. The speed of the bicycle is determined by the speed of the rear wheel, which is proportional to the speed of the cogwheel. The speed of the cogwheel is proportional to the speed of the chainwheel, which is proportional to the pedaling rate. Therefore, the pedaling rate is proportional to the speed of the bicycle.

In a Bicycle, the Pedals Drive the Chainwheel, Which Is