Question

A clock pendulum keeps correct time at ${25}^{\circ }C$. If the pendulum is made of steel whose $\alpha =1\times {10}^{-5}{/}^{\circ }C$, how many seconds per day will it gain or loose when used at ${40}^{\circ }C$ ?

• A. 12.96 s
• B. 6.48 s
• C. 3.24 s
• D. 8.64 s

Answer 1

Answer: (B)

6.48 s

Loss or gain of time per day

$=\frac{1}{2}\alpha △t\times 86400=\frac{1}{2}\times 1\times {10}^{-5}\times 15\times 86400=6.48s$