Mass Formula

Mass Formulas - Difference Between Mass and Weight

Mass is a quantity that gives an idea about how much matter is present in an object. It is a quantitative measure of inertia. So acceleration is inversely proportional to inertia.

The relation between force and mass is given by:
                 F = ma or m = F/m
The relation between density, mass, and Volume is given by:
                 𝛒 = m/V or m = 𝛒V
The relation between Kinetic energy, mass, and velocity is given by:
                 K = ½ mv2 or m = 2K/v2
The relation between Potential energy, mass, the acceleration due to gravity and height is given by:
                 P = mgh or m = P/gh
The well known Einstein’s mass-energy relation that provides mass energy formula as
                   m = E / c2
Where, E = energy, m = mass, c = speed of light
The relation between mass(m), velocity(v) and momentum(p) is given by:
                    p = mv or m = p/v

Difference between mass and weight:
Weight is the force due to gravity on a mass. So mass remains constant but weight changes as per the change in the gravitational field.
                W = mg or m = W/g

Example:
Calculate the mass of a body if the density and volume of a body are 2 Kg/m3 and 5 m3.
Ans:
Here mass = density x volume
                  = 2 x 5
                  = 10 Kg

Question:
If an object is moving with a velocity of 5 m/s and has a kinetic energy of 100J, Find the mass.