Question

A copper ball of mass $100\, gm$ is at a temperature $T$. It is dropped in a copper calorimeter of mass $100\, gm$, filled with $170\, gm$ of water at room temperature. Subsequently, the temperature of the system is found to be $75^{\circ} C$. $T$ is given by : (Given : room temperature = $30^{\circ}C$, specific heat of copper = $0.1\, cal\,g^{-1}\,^{\circ} C^{-1}$)

• A. $800^{\circ}C$
• B. $885^{\circ}C$
• C. $1250^{\circ}C$
• D. $825^{\circ}C$

Answer 1

Answer: (B)

$885^{\circ}C$

Answer 2

$100 \times 0.1 \times (t - 75) = 100 \times 0.1 \times 45 + 170 \times 1 \times 45$
$10t - 750 = 450 + 7650$
$10t = 1200 + 7650$
$10t = 8850$
$t = 885^{\circ} C$