Physics Formulas

Energy Formula Physics


Energy is a very important concept in Physics. We can define energy as the strength to do any kind of physical activity. Therefore, we can say that Energy is the ability to do work. Resources are processed to get the energy that is used to provide light or heat for many purposes. We may also compare two persons and concluding that one person has more energy than another person. Thus, we can say that different types of energy can never be created nor destroyed. Also, energy can only be transformed from one form to another form. In this article, we will discuss the concept of energy and energy formula physics with examples. Let us learn the concept!

energy formula physics


Energy Formula Physics

Concept of Energy:

Energy is of mainly two types, Kinetic energy, and Potential energy. Also, there are two forms of energy sources such as renewable sources of energy and Non-renewable source of energy. For example, Renewable sources are solar energy, Wind Energy, and Geothermal energy. On the other hand, Non-renewable sources are Natural gas, Coal and Petroleum products.

The SI unit of energy is Joules (J) which is also termed as Newton-meter. When a certain amount of force in Newton is applied to an object and it moved a certain distance in meters, then the energy applied will be Joules i.e. Newton-meters.

We have to consider potential and kinetic energy in a much detailed way, which are thermal, potential and kinetic energy. Sometimes chemical potential energy is also observed at a broad level. Similar remarks may apply to nuclear potential energy and most other forms of energy.

The formula for Energy:

Kinetic Energy: The energy exists due to the motion of an object is known as Kinetic Energy. For example, a moving van, flowing water, etc.

\(K.E. = \frac{1}{2} \times m \times v^2\)


K.E. Kinetic Energy
m Mass of the object
v The velocity of the object

Potential Energy: This is the energy stored in an object due to its position and height. It is measured by the amount of work done. For example, a book on a table, water stored in a lake, etc.

\(P.E. =m \times g \times h\)


P.E. Potential Energy
m Mass of the object
g Acceleration due to gravity
h Height

Mechanical Energy: It is the sum total of potential energy and kinetic energy which is the energy associated with the motion & position of any object. Therefore, the formula of mechanical energy will be:

Mechanical Energy = Kinetic Energy + Potential Energy

The law of conservation of energy is one of the basic laws of Physics. It states that “In a closed and isolated system from its surroundings, the total energy of the system will be conserved.” Thus energy can neither be created nor destroyed, although it can only be transformed from one form to another.

Solved Examples

Q.1: Calculate the kinetic energy of a 25 kg object which is in the moving state with a velocity of 120 \(ms^{-1}\).


m = 25 kg

\(v = 120 ms^{-1}\)

Formula for kinetic energy is:

\(KE = \frac{1}{2} \times m \times v^2 \)

= \(\frac{1}{2} \times 25 \times 120^2 \)

= \(25 \times 60 \times 120\)

= \(180 \;KJ\)

Therefore kinetic energy will be 180 Kilo Joules.

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