Momentum vs Impulse
Momentum is a property of a moving body and describes the force that is required to stop a moving body. When we say that a particular team has momentum at the moment, we mean to say that the team is on a roll and hard to be stopped by other teams in the tournament. Any object having momentum needs a force against it, and this force also needs to be applied for some time to stop the body. More the momentum, harder is it to stop a body. So it is clear that a moving body with a momentum can be stopped if a particular force is applied against it for some time.
According to Newton’s 2nd law of motion, Force is the product of mass and the acceleration of a body. Now acceleration is rate of change of velocity, so we can say that
F = m X a
= m X v1 -v2/t = m(v1 -v2)/t
In this equation, if we multiply both sides by t, we get new equation as F X t = m X (v1 -v2); F. t = m(v1 -v2)
On the right side of the equation is change in momentum of the body, and on the left side is an important property of the body known as Impulse.
Thus Impulse = change in momentum
Impulse is an important concept in the study of collisions and the above equation is an important one known as impulse-momentum change equation. When we talk about impulse, we are really talking about change in momentum of a moving body, and the rate of change in momentum is the force applied upon the body.
Examples:
