$A$ metal ball of mass $100 \ g$ at $20^{\circ} C$ is dropped in $200 \ ml$ of water at $80^{\circ} C$. If the resultant temperature is $70^{\circ} C$,then the ratio of specific heat of the metal to that of water is

$A$ calorimeter contains $0.5 \,kg$ of water at $30^{\circ} C$. When $0.3 \,kg$ of water at $60^{\circ} C$ is added to it, the resulting temperature is found to be $40^{\circ} C$. The water equivalent of the calorimeter is (in $\,kg$)

Two identical bodies are made of a material for which the heat capacity increases with temperature. One of these is held at a temperature of $100^{\circ} C$,while the other one is kept at $0^{\circ} C$. If the two are brought into contact,then assuming no heat loss to the environment,the final temperature that they will reach is

$A$ copper ball of mass $100 \ gm$ is at a temperature $T$. It is dropped into 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......$^\circ C$ (Given: room temperature $= 30 ^\circ C$,specific heat of copper $= 0.1 \ cal/gm ^\circ C$)

When $100\,g$ of a liquid $A$ at $100\,^oC$ is added to $50\,g$ of a liquid $B$ at temperature $75\,^oC$,the temperature of the mixture becomes $90\,^oC$. The temperature of the mixture,if $100\,g$ of liquid $A$ at $100\,^oC$ is added to $50\,g$ of liquid $B$ at $50\,^oC$,will be ........$^oC$

$A$ calorimeter contains $0.2 \ kg$ of water at $30^{\circ}C$. When $0.1 \ kg$ of water at $60^{\circ}C$ is added to it,the final temperature of the mixture becomes $35^{\circ}C$. What is the heat capacity of the calorimeter in $J/K$?