Question

If you drop a 25 gram piece of metal that has a temperature of 100° Celsius into 1000 grams of water at 20°Celsius, what best describes what would occur? A) The temperature lost by the metal will equal the temperature gained by the water. B) The heat lost by the metal will equal the heat gained by the water. C) The final temperature will be 60°Celsius. D) The final temperature will be more than 60°Celsius.

Answer 1

B. The heat lost by the metal will equal the heat gained by the water

Answer 2

Answer : The correct option is, (B) The heat lost by the metal will equal the heat gained by the water.

Explanation :

According to the conservation of heat law, the heat given by the hot body is equal to the heat taken by the cold body.

Heat loss = Heat gained

$Q_{absorbed}=-Q_{released}$

As we know that,  

$Q=m\times c\times \Delta T=m\times c\times (T_{final}-T_{initial})$

$m_1\times c\times (T_{final}-T_1)=-[m_2\times c\times (T_{final}-T_2)]$

where,

$m_1$ = mass of hot body

$m_2$ = mass of cold body

$T_{final}$ = final temperature

$T_1$ = temperature of hot body

$T_2$ = temperature of cold body

c = specific heat

So, the question follow that conservation of heat law that is the heat given by the hot body is equal to the heat taken by the cold body because the given metal is act as hot body and the water act as a cold body.

Hence, the correct option is, (B)