**Heat Capacity and Specific Heat**

Heat capacity is a physical property of a substance that quantifies the amount of heat energy required to raise the temperature of a given amount of the substance by a certain amount. It is denoted by the symbol C and has units of joules per Kelvin (J/K). The heat capacity of a substance depends on its mass, chemical composition, and physical state.

On the other hand, specific heat is a measure of the heat capacity per unit mass of a substance. It is denoted by the symbol c and has units of joules per kilogram per Kelvin (J/kg·K). Specific heat is an intensive property, meaning it is independent of the amount of substance present.

**Calculating Specific Heat**

To calculate the specific heat (c) of a substance, we can use the formula:

c = C/m

Where:
- c is the specific heat
- C is the heat capacity
- m is the mass of the substance

In this case, the heat capacity (C) is given as 750 J/K and the mass (m) is given as 15 kg. We can substitute these values into the formula to find the specific heat:

c = 750 J/K / 15 kg
c = 50 J/kg·K

Therefore, the specific heat of the substance is 50 J/kg·K.

**Explanation**

The specific heat of a substance is a measure of how much heat energy is required to raise the temperature of 1 kilogram of the substance by 1 Kelvin. In this case, the specific heat of the substance is 50 J/kg·K, which means that it takes 50 joules of heat energy to raise the temperature of 1 kilogram of the substance by 1 Kelvin.

Specific heat is an important property in thermodynamics as it helps in understanding how substances store and release heat energy. It is used in various calculations, such as determining the amount of heat transferred during a temperature change or calculating the final temperature when two substances of different temperatures are mixed. Knowing the specific heat of a substance can also be useful in designing and optimizing heating and cooling systems.

In conclusion, the specific heat of the substance is 50 J/kg·K, which represents the amount of heat energy required to raise the temperature of 1 kilogram of the substance by 1 Kelvin.

50 jk/kg?