JEE Main Physics question

PhysicsWork, Energy and PowerJEE Main

A block of mass at the end of a string is whirled round in a vertical circle of radius . The critical speed of the block at the top of its swing, below which the string would slacken before the block reaches the top, is

Answer: (D)

Solution

Minimum speed at the top for the string to stay taut: .

Question ID VK-158215