When a body like earth is moving in a circular path the work done in that case is zero because: (a) Centripetal force acts in the direction of motion of the body (b) Centripetal force acts along the radius of circular path (c) Gravitational force acts along the radius of circular path (d) Centrifugal force acts perpendicular to the radius of circular path

(b) Centripetal force acts along the radius of circular path

Explanation:

Centripetal force is a force experienced by a body moving in a circular path. It is expressed mathematically ad F = mv²/r

m is the mass of the body

v is the velocity

r is the radius of the circular path

When a body moves in a circular path, work dome is zero because Centripetal force acts along the radius of circular path and the force is at right angle with the motion of body.

answer is c

explanation:

weight of the box is given as

here this is placed on the inclined of angle 42 degree

now this weight will have two components one is along the incline other is perpendicular to it

so here we need to apply a force parallel to incline opposite to its component of weight

so here the component of weight is given as

here we have

so it requires 75 n force to move it upwards