What is Linear Momentum?
Linear momentum is defined as the product of mass of the particle and its velocity, it is a vector quantity.
From newton’s second law of motion, for a fixed mass particle
For a system of n particles with masses and velocities respectively, then the net momentum of the system is
Differentiating the above expression with respect to time
The magnitude of linear momentum may be expressed in terms of kinetic energy as well
Law of Conservation of Momentum
If the net force acting on a body is equal to zero, then the momentum of the body remains constant. This is known as law of conservation of momentum.
Therefore, pnet = 0 or pnet = constant
If the velocity of centre of mass is equal to zero, then from we get,
If the velocity of centre of mass is constant (vcm = constant) then we get = constant.
This is known as the law of conservation of linear momentum of the system of particles.
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