## 2 Comments

AeonErion, 9 May, 2011 @ 01:37

Author Comment

I need an explanation on how to get the answer, please?

bunnyfrog, 17 Jun, 2011 @ 13:39

Comment

Ok, so think about your equations of motion, for example v=u+at, or in the case of this question E_{k}= 1/2 mv^{2} or to spell it out, kinetic movement equals half (mass times velocity squared).

So, the change in momentum obviously does not equal zero, so that removes A. Of the other answers, which corresponds to the equation of movement that you need?