Question

When the bob of a simple pendulum swings, the work done by tension in the string is

• A.

  0

• B. < 0
• C. zero
• D. maximum

Answer 1

Answer: (C)

zero

Answer 2

Tension in the string is along the radius of circular path adopted by the bob, while displacement of the bob is along the circumference of the path. Hence, again $\vec{F}$ and$\vec{ s }$ are at $90^{\circ}$ and so, $W = 0$.