# 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.

1
by anuragmirdha

2014-08-26T05:49:39+05:30

### This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Let us say mass of the friends is m kg each. For example...

We apply the conservation of momentum principle here. Let us say the ball of 2 kg is thrown with a velocity u by one friend on the left, towards his friend on the right. We take u as the horizontal component of velocity. Initially the friends were stationary. Let the friend on the left move further left with a velocity v.

m v + 2 kg * u = 0      v = - 2 u / m

Let us say the second friend move further to right with a velocity V after catching the ball.

2 * u + m * 0 = (m+2) * V

V = 2 u / (m+2)

The friends separate with a relative speed =

V - v =  2u / (m+2)  + 2 u / m
= 2 u  [ 2m + 2 ]  / m (m+2)

= 2 u  * 2m / m * m      = 4 u / m          if  m >>2 kg

click on thank you and on stars. click on brainlyest