A stone tied to a string of length is whirled in a vertical circle with the other end…
PHYSICS · Single correct · A Level · Physics · Further mechanics and thermal physics · Further mechanics and thermal physics
Problem
A stone tied to a string of length L is whirled in a vertical circle with the other end of the string at the centre. At a certain instant, the stone is at its lowest position and has speed u. What is the magnitude of the change in its velocity as it reaches a position where the string is horizontal?
(1) u2−2gL
(2) 2gL
(3) u2−gL
(4) 2(u2−gL)