A 1.0-kg ball on the end of a string is whirled at a constant speed of 2.0 m/s in a horizontal circle of radius 1.5 m. What is the work done by the centripetal force during one revolution

The work done by the centripetal force is always, zero.

Explanation:

The formula for the work done by a force on an object is given as follows:

W = F d Cos θ

where,

W = Magnitude of the Work Done

F = Force applied to the body

θ = Angle between the direction of force and direction of motion of the object

In case of the circular motion, the force is the centripetal force. The centripetal force is always directed towards the center of the circle. While, the object moves in a direction, which is tangential to the circle. Hence, the angle between them is always 90°. Therefore,

W = F d Cos 90°

W = F d (0)  

W = 0 J

Hence, the work done by the centripetal force is always, zero.