Heat Formula

Introduction to Heat

Heat is the form of energy transferred between systems or objects due to a temperature difference. It always moves from a body at a higher temperature to the one at a lower temperature.

Units: The SI unit of heat is the joule (J); in many practical and historical contexts, calories are used, but it is essential to recognize that 1 calorie equals 4.184 joules.

The Specific Heat formula is

Heat equation 1

Where,

• m The mass of the body

• C Specific heat

• ΔT Temperature difference

Heat equations can be used to find the transfer of heat, mass, specific heat or temperature difference.

Heat is measured in terms of Joules (J).

Solved Example

Calculate the amount of heat needed to raise half a kg of iron from 250 C to 600 C?

Solution:

Given parameters are

Mass m = 0.5 Kg,

Specific heat of iron c=

Temperature difference 

the heat formula is given by

Q = m × c × Δ T

= 10.125 x 103J

Example 2

Calculate the amount of heat energy that is lost when the water of 5 Kg mass is cooled from 60°C to 20°C. Given the Specific heat of water C =

Solution:

Given parameters are,

The mass of water is 5 Kg,

The specific heat of water C is 

Temperature difference Δ T is 40°

The formula for the amount of heat energy is given by

Q = m x C x Δ T

   = 5 × 4.2 ×10340

   =84.0103J

Conclusion

Understanding the heat formula and concepts of latent heat can help solve problems related to a change in temperature or change of phase. Practice various problems to strengthen your understanding of these concepts.