Heat and Thermodynamics 1 Question 9
9. A copper ball of mass $100 g$ is at a temperature $T$. It is dropped in a copper calorimeter of mass $100 g$, filled with $170 g$ of water at room temperature. Subsequently, the temperature of the system is found to be $75^{\circ} C$. T is (Given, room temperature $=30^{\circ} C$, specific heat of copper $=0.1 cal / g^{\circ} C$ )
(2017 Main)
(a) $885^{\circ} C$
(b) $1250^{\circ} C$
(c) $825^{\circ} C$
(d) $800^{\circ} C$
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Answer:
Correct Answer: 9. (a)
Solution:
- Heat gained (water + calorimeter) $=$ Heat lost by copper ball
$\Rightarrow m _w s _w \Delta T+m _c s _c \Delta T=m _B s _B \Delta T$
$\Rightarrow 170 \times 1 \times 45+100 \times 0.1 \times 45$ $=100 \times 0.1 \times(T-75)$
$\therefore \quad T=885^{\circ} C$
