Question

A 41 kg rock accidentally breaks loose from the edge of a cliff and falls straight down. The magnitude of the air resistance that opposes its downward motion is 260 N. How much air resistance would cause the rock to fall at a constant speed?

Answer 1

Downward force acting on the rock is its weight i.e `41g N`

so,in order to make it move constantly,air resistance of equal magnitude is required to balance the downward force on the rock due to its weight,so that it will go down with constant velocity at equilibrium.

So,required air resistance is `41*g=401.8N`

now,given,available air resistance is `260N`,so `401.8-260=141.8N` of more air resistance will be required.