A bicycle is supported so that it is stopped from falling sideways but can move forwards or backwards; its pedals are in their highest and lowest positions.
A student crouches beside the bicycle and applies a horizontal force, directed towards the backwheel, to the lower pedal.
(i) Which way does the bicycle move?
(ii) Does the chain-wheel rotate in the similar or opposite sense as the rear wheel?
(iii) Which way does the lower pedal move relative to the ground?