Mechanical Engineering - Thermodynamics - Discussion

What is this water equivalent?

Heat Capacity (H) or thermal capacity.

The amount of heat required to change the temperature by 1 kelvin of a substance is called its Heat Capacity. Unit will be joule/K.

Water Equivalent : (W).

For any given substance the equivalent mass of water W having the same specific heat as the given substance is called its Water Equivalent.
Unit will be gram or Kg.

Now how can numerical value be same for these two ?

How can both be same?

I think that steam is produced from water and here we given that only liquid so that we can't say its evaporation from water so the answer is incorrect.

Heat capacity is the ratio heat added and due to this raise in temperature t is called heat capacity.

Water equivalent of a substance is the amount of water that would absorb the same amount of heat as the substance per degree rise in temperature.

Explanation: The quantity of heat that raises the temperature of some substance by some amount, the same quantity of heat that can raise the same temperature of a certain mass of water; the mass of water is then called water equivalent.

The heat absorbed or lost by a substance = water equivalent of the substance °- temperature increase or decrease.

For example, if we say the water equivalent of a substance is 20 gm, we understand that the heat that is required to raise the temperature of the substance by 1°C can be used to raise the temperature of 20 gm of water by 1°C.

The heat capacity and water equivalent both are equal to the product of the mass of a substance and specific heat. Thus their numerical values are equal. But the units are different. By heat capacity we mean some amount of heat whereas by water equivalent we mean some mass of water.

Answer is wrong. Because materials are different Water and some other. We have to raise the temperature by one degree. The Amount of heat will be different.

The heat capacity and water equivalent both are equal to the product of the mass of a substance and specific heat. Thus their numerical values are equal. But the units are different.