Understanding Elastic Collision in Billiard Balls

Conservation of Momentum in Elastic Collision

Momentum is Conserved: In an elastic collision, both momentum and kinetic energy are conserved. The momentum of an object is the product of its mass and velocity. When two billiard balls collide elastically, the total momentum before the collision is equal to the total momentum after the collision.

Calculating the Final Velocity of the Second Ball

Let's denote the mass of each billiard ball as m. Initially, the first ball is moving at 4 m/s and the second ball is at rest. Using the equation for conservation of momentum:

m1*v1 = m2*v'2

Where: m1 = mass of the first ball v1 = initial velocity of the first ball m2 = mass of the second ball v'2 = final velocity of the second ball

Since both balls have the same mass, the equation simplifies to:

4 m/s = v'2

Therefore, the final velocity of the second ball is 4 m/s as well. This confirms that it is an elastic collision, where both momentum and kinetic energy are conserved.