A patient of mass 75kg sits in a wheelchair of mass 30kg. What is the force needed to push both up a 30 degree slope? If the carer stops on the 30 degree slope and applies the brake, what is the magnitude and direction of the frictional force preventing the wheelchair from rolling back down?

Answer 1

on the slope, there are three forces

Force pushing- force down the plane-frictional force= ma assuming constant speed, (a=0) then

force pushing= mgSin30+friction. If you assume rolling friction is zero, you have it.

Now, if stopped

mgsin30=frictional force

this seems too easy.