Steven carefully places a =1.95 kgm wooden block on a frictionless ramp so that the block begins to slide down the ramp from rest. the ramp makes an angle of =54.3° up from the horizontal. which forces do nonzero work on the block as it slides down the ramp?

The forces that do non-zero work on the block are gravity and normal reaction force

Explanation:

In this question we have given,

mass of the wooden block,

angle between ramp and horizontal surface,

in this case ramp is friction less so friction force will be zero and hence work done due to friction force will be zero.

As wooden block is sliding down due to gravity(gravity is pulling the block in downward direction).

so two forces will act on wooden block as it slides down the ramp that are gravity and normal reaction force.  

Therefore, the forces that do non-zero work on the block are gravity and normal reaction force.

it doesn't. it was imagined up in the middle ages.

i don't understand. explain it clearly