Question

A mass attached to one end of a string crosses top-most point on a vertical circle with critical speed. Its centripetal acceleration when string becomes horizontal will be ______. (g = gravitational acceleration)

Options

• g

• 3g

• 4g

• 6g

Answer 1

A mass attached to one end of a string crosses top-most point on a vertical circle with critical speed. Its centripetal acceleration when string becomes horizontal will be 3g. (g = gravitational acceleration)

Explanation:

Speed at top most point, v = `sqrt(3"rg")`

Centripetal acceleration, a_c = `"v"^2/"r"=(3"rg")/"r"=3"g"`