Q. A clock pendulum made of invar has a period of $2\, s$ at $20^{\circ} C$. If the clock is used in a climate where average temperature is $40^{\circ} C$, what correction (in seconds) may be necessary at the end of $10$ days to the time given by clock? $\left(\alpha_{\text {invar }}=7 \times 10^{-7 \circ} C ^{-1}, 1 \text { day }=8.64 \times 10^{4} s \right)$
Thermal Properties of Matter
Solution: