Momentum

Momentum is defined as the product of mass and velocity.

Momentum is a vector quantity. It has both magnitude and direction.

The SI unit of momentum is kgms^{-1}

Formula:

Example 1

A student releases a ball with mass of 2 kg from a height of 5 m from the ground. What would be the momentum of the ball just before it hits the ground?

Answer:

In order to find the momentum, we need to know the mass and the velocity of the ball right before it hits the ground.

It's given that the mass, m = 2kg.

The velocity is not given directly. However, we can determine the velocity, v, by using the linear equation of uniform acceleration.

This is a free falling motion,

The initial velocity, u = 0

The acceleration, a = gravirational acceleration, g = 10ms^{-2}

The dispacement, s = high = 50m.

The final velocity = ?

From the equation

v^{2} = u^{2} + 2as

v^{2} = (0)^{2} + 2(10)(5)

v = 10ms^{-1}

The momentum,

p = mv =(2)(10) = 20 kgms^{-1}

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shafique// March 12, 2009 at 9:04 AMvery informative :) thanks !

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eka// February 7, 2011 at 1:11 AMTAHNKSSSSS A LOTTT XD .