Two friends on roller-skates are standing 5 m apart facing each other. One of them throws a ball of 2 kg towards the other, who catches it. How will this activity affect the position of the two? Explain your answer.
Sol.
As the first friend throws the ball away from him, he will be pushed backwards. This occurs due to the conservation of linear momentum principle. Now when the second front catches the ball, he moves in the direction of motion of the ball. This also occurs, due to conservation of momentum principle.
Therefore, in this Phenomenon: both the friends will move in the opposite direction.
This motion will cause: increase in separation between them.