M = mass of the ball A = 5.0 kg
m = mass of the ball B = ?
V = initial velocity of the ball A before collision = 20 m/s
v = initial velocity of the ball B before collision = 10 m/s
V' = final velocity of the ball A after collision = 10 m/s
v' = final velocity of the ball B after collision = 15 m/s
using conservation of momentum
M V + m v = M V' + m v'
(5.0) (20) + m (10) = (5.0) (10) + m (15)
100 + 10 m= 50 + 15 m
5 m = 50
m= 10 m/s
The mass of unknown ball is of 10 kg.
What is Conservation of Momentum?
The conservation of momentum says that, "When there is a collision between the two objects, then the momentum of each object before the collision is equal to the momentum of objects after the collision.
Given data:
The mass of the first ball is, m = 5.0 kg.
The speed of the first ball is, u = 20 m/s.
The speed of unknown ball is, u' = 10 m/s.
Speed of first ball after collision is, v = 10 m/s (same direction).
Speed of second ball after collision is, v' = 15 m/s (same direction).
Since each ball has the same direction, before and after the collision. So, the expression for the conservation of linear momentum is,
mu + Mu' = mv + Mv'
here,
M is the mass of unknown ball.
Solving as,
(5 × 20) + (M × 10) = (5 × 10) + (M × 15)
100 + 10M = 50 + 15M
50 = 5 M
M = 10 kg
Thus, we can conclude that the mass of unknown ball is of 10 kg.
Learn more about the conservation of linear momentum here:
https://brainly.com/question/2141713
