Question

A piece of lead falls from a height of 100m on a fixed non-conducting slab which brings it to rest. The temperature of the lead piece immediately after collision increases by (Sp.heat of lead is 30.6cal/kg/${}^{0}C$ and $g=9.8m/se{c}^2.$)

• A. 0K
• B. ${27}^{0}C$
• C. 7.62K
• D. 4.2K

Answer 1

The correct option is C 7.62K

When the lead ball falls on the non-conducting surface, the lost potential energy is absorbed by the ball as heat energy.

$mgh=mc\Delta T$

$\Delta T=\frac{\left(9.8\right)\left(100\right)}{(30.6\times 4.2)}=7.625K$