Question

. A mass 'm' of lead shot is placed at the bottom of a vertical cardboard cylinder that is 1.5 m long and
closed at both ends. The cylinder is suddenly inverted so that the shot falls 1.5 m. If this process is
repeated quickly 100 times, assuming no heat is dissipated or lost, the temperature of the shot will
increase by [Specific heat of lead = 0.03 cal g ' °C-']
(A) 0
(B) 5 °C
(C) 7.3 °C
(D) 11.3 °C
​

Answer 1

Answer:

D

Explanation:

Specific heat of lead=0.03kcal/kg∘C. Gravitational potential energy is converted into thermal energy which is absorbed by the lead shot. If T0 is the rise in temperature of the shot, then

(100)[mgh]=(m×s×T)J

T=100×g×hJs=100×9.8×1.50.03×4.18×103.∘C=11.3∘C