A stone is attached to a string and whirled clockwise in a vertical circle at…
PHYSICS · Multi-part · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics
Problem
A stone is attached to a string and whirled clockwise in a vertical circle at constant speed.
(i) Explain why keeping the speed constant does not mean that the velocity of the stone remains constant.
(ii) For each of the following positions of the stone—top of the circle, right-hand side, and bottom of the circle—describe the direction of the force that keeps the stone in circular motion.
(iii) For the same three positions, describe the direction of the velocity of the stone.
(iv) A student claims that an outward force acts on the stone while it moves in the circle. Give reasons to accept or reject this claim.