Question

A simple pendulum with angular frequency ω oscillates simple harmonically. The tension in the string at lowest point is T. The total acceleration of the bob at its lowest position is

• A. (T/m – g)
• B. Zero
• C. g – T/m
• D. T + g/m

Answer 1

Answer: (A)

(T/m – g)

Answer 2

At the lowest point, the tangential acceleration = 0, but since the bob is moving in a circle, it will have centripetal acceleration. Centripetal force = T – mg

⇒ centripetal acceleration = $\frac{T - mg}{m} = \frac{T}{m}$-g