Answer:
(a) 2.03 m/s
(b) 2.15 m/s
Explanation:
(a)
From the law of conservation of momentum, the sum of initial momentum equals the sum of final momentum
Momentum, p=mv where m is the mass and v is the velocity
where is the common velocity, and are velocities of the first railroad car and the second railroad car respectively, and are masses of the first railroad car and the second railroad car respectively
Substituting the given figures then
(b)
Momentum, p=mv where m is the mass and v is the velocity
where and are initial velocities of the ball moving towards west and the other ball moving in opposite direction respectively, and are masses of the first railroad car and the second railroad car respectively
Taking west as positive then the opposite direction will be negative hence
Note that when the 0.455 rebounds, it moves towards East and since we took West as positive that is why we give 15.4 as a negative value.
towards East