The drawing $($Figure P$4)$ represents a bicycle with an $800-N$ rider applying full weight to one pedal. Treat this as a twodimensional problem, with all components in the plane of the paper. Draw as free bodies in equilibrium:

$($a$)$ The pedal, crank, and pedal sprocket assembly.

$($b$)$ The rear wheel and sprocket assembly.

$($c$)$ The front wheel.

$($d$)$ The entire bicycle and rider assembly.