On what principle does a bicycle work ? What is the mechanical advantage of a bicycle? Determine the velocity ratio of a bicycle in which the ratio of teeth on the rear sprocket wheel to that on the front wheel is 1: 3.

Explanation

(i) Consider how the effort applied is transmitted.
(ii) Bicycle uses more than one simple machine.
(iii) Let L = length of pedal
E = effort applied on pedal
W = load to be overcome
R = radius of rear wheel
(iii) Find the M.A. of cycle using principle of lever: effort `xx` displacement of effort = load `xx` displacement of load
`M.A. = (W)/(E)`
(iv) Velocity ratio = ratio of number of teeth on front wheel to that on rear sprocket wheel