Question

If the length of second's pendulum is decreased by 2%, how many seconds it will lose per day

• A. 3927 sec
• B. 3727 sec
• C. 3427 sec
• D. 864 sec

Answer 1

Answer: (D)

864 sec

Answer 2

$T \propto \sqrt{l}$⇒ $\frac{\Delta T}{T} = \frac{1}{2}\frac{\Delta l}{l} = \frac{0.02}{2} = 0.01$⇒$\Delta T = 0.01T$

Loss of time per day

$= 0.01 \times 24 \times 60 \times 60 = 864\sec$