Answer:
The magnitude of the velocities of the two balls after the collision is 3.1 m/s (each one).
Explanation:
We can find the velocity of the two balls after the collision by conservation of linear momentum and energy:
Where:
m₁: is the mass of the ball 1 = 100 g = 0.1 kg
m₂: is the mass of the ball 2 = 300 g = 0.3 kg
: is the initial velocity of the ball 1 = 6.20 m/s
: is the initial velocity of the ball 2 = 0 (it is at rest)
: is the final velocity of the ball 1 =?
: is the initial velocity of the ball 2 =?
(1)
Now, by conservation of kinetic energy (since they collide elastically):
(2)
By entering equation (1) into (2) we have:
By solving the above equation for :
Now, can be calculated with equation (1):
The minus sign of means that the ball 1 (100g) is moving in the negative x-direction after the collision.
Therefore, the magnitude of the velocities of the two balls after the collision is 3.1 m/s (each one).
I hope it helps you!