Question

two spherical balls of 2kg and 3kg masses are moving towards each other with velocities of 6 metre per second and 4 metre per second respectively. what will be the velocity of smallar ball after collision if velocity of 3 kg mass is 3 metre per second..​

Answer 1

Answer:

Since the direction of the the balls aren't mentioned, let's assume they move in a straight line and against each other (opposite directions)

And also, lest assume there are no losses involved. In reality, when two balls collide, there are energy losses in the form of friction, sound, deformation of the balls, etc. But for simplicity, let's assume, it's a perfect elastic collision.

According to law of conservation of momentum, the total momentum of the system is always conserved, i.e., the sum of momentums of the balls before collision is equal to the sum of momentums of the balls after collision.

Momentum is the product of mass of the ball and the velocity of the balls. Let m denote the mass of the balls. Let u and v be the initial and final velocities of the balls. Let subscripts 1 and 2 denote the first and the second ball.

According to the law of conservation of momentum.

m1u1−m2u2=m1v1−m2v2

2×6−3×4=2×v1−3×3

12−12=2v1−9

2v1=9

v1=4.5

The velocity of the smaller ball after collision will me 4.5 m/s. But in the opposite direction of the first body.