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

The correct option is D

864 sec

T ∝ $\sqrt{l}\Rightarrow \frac{\Delta T}{T}=\frac{1}{2}\frac{\Delta l}{l}=\frac{0.02}{2}=0.01\Rightarrow \Delta T=0.01T$

Loss of time per day = 0.01 $\times$ 24 $\times$ 60 $\times$ 60 = 864 sec