Question

Suppose the amplitude of a simple pendulum having a bob of mass m is θ. Find the tension in the string when the bob is at its extreme position.

Answer 1

Follow the Diagram attached below.

Now, We know that at Extreme Positions the velocity of the body is zero.

Therefore, the Net Force towards the center or commonly the Centripetal Force is zero.

∴ F = mv²/r

F = 0

∵ T =  mg Cos θ + F

∴ T =  mg Cos θ + 0  [Since, Centripetal Force will be zero).

Hope it helps.

Answer 2

Follow the Diagram attached below.

Now, We know that at Extreme Positions the velocity of the body is zero.

Therefore, the Net Force towards the center or commonly the Centripetal Force is zero.

∴ F = mv²/r

F = 0

∵ T =  mg Cos θ + F

∴ T =  mg Cos θ + 0  [Since, Centripetal Force will be zero).

Hope it helps.