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 $=0.1\; cal/gm^{\circ}C)$
