A simple pendulum of length L swings in a vertical plane. The tension of the string when it makes an angle `theta` with the vertical and the bob of mass m moves with a speed v is (g is the gravitational acceleration)

Options

A. `mv^(2)//L`
B. `mg cos theta + mv^(2)//L`
C. `mg cos theta -mv^(2)//L`
D. `mg cos theta`

Answer

B

Explanation

Given situation is shown in the figure. Where, L = length of pendulum m= mass of the bob 0= angle between pendulum and vertical v = speed of pendulum Let, T be the tension in the string at given situation. mg sino mg mg cos e Acceleration of the bob = `v^(2)/L`

Using newton.s second law of motion, `F_(net) = (mv^(2))/L`
`T - mg cos theta =(mv^(2))/L`
`T = mg cos theta + (mv^(2))/L`