Can centripetal force ever do work on an object?

A0.580-kg rock is tied to the end of a string and is swung in a circle with a radius of 0.500 meters. the velocity of the rock is 4.50 m/s. what is the centripetal force acting on the rock? 15.5 n 5.22 n 69.8 n 23.5 n

Suppose that 27 j of work is needed to stretch a spring from its natural length of 6 m to a length of 9 m. (a) how much work is needed to stretch the spring from 12 m to 14 m? j (b) how far beyond its natural length will a force of 78 n keep the spring stretched?

An airplane is flying with a velocity of 240 m/s at an angle of 30.0∘ with the horizontal, as the drawing shows. when the altitude of the plane is 2.4km,a flare is released from the plane. the flare hits the target on the ground. what is the angle θ?