Mechanical Energy Formula

The total mechanical energy is the sum of all potential energies and all kinetic energies of an object that is utilized to carry a specific work. The potentiality of an element due to a certain configuration or a motion or both of the latter can be defined as mechanical energy also. The position gives the potential energy, while motion gives the kinetic energy for any object. A potential energy of an object is zero when it's in the movement and Kinetic energy is zero when the object is in rest.

Formula

M. E = K. E + P. E

M. E = ½ mv2 + mgh

Where,  

m = mass of that object

v= velocity of that object 

g = acceleration due to gravity 

h   =  height of that object.

Solved Example

Example 1: A boy  is sitting on a 20 m height building and his mass is 50 kg. Calculate the mechanical energy?

Solution:

Given,

m = 50 kg

h = 20m

the man is not moving, therefore, K. E = 0

The formula of mechanical energy

M.E = 1/2 mv2 + mgh

Since K.E is 0, the equation becomes,

M.E = mgh

M.E = 50 ×9.81 ×20

M.E  = 9810 J