Question

A simple pendulum of mass $m$ and length $L$ swings simple harmonic motion about vertical equilibrium position $(\theta =0)$. If maximum angular displacement of pendulum is ${\theta }_{max}$. Calculate the tension in the connecting rod at ${\theta }_{max}$.

• A. $mgsin{\theta }_{max}$
• B. $mgcos{\theta }_{max}$
• C. $mgLsin{\theta }_{max}$
• D. $mgLcos{\theta }_{max}$
• E. $mgL(1-cos{\theta }_{max})$

Answer 1

The correct option is B $mgcos{\theta }_{max}$

Let the tension in the string when the bob is at the maximum displacement be $T$

The gravitational force mg is resolved as shown in the figure.

$\therefore$ $T=mg{\theta }_{max}$