impact, the ball moves back along the original path and then hits with balls Z and Y which have the samw mass as X. assume all impacts are elastic, which of the following is/are correct?
1.KE and momentum of the ball X are both conserved before and
after impacts with the wall
2.the momentum of the system of balls X and Y is conserved before
and after ball X impact whit Y and Z
3.for the system of balls X,Y ,Z, the momentum of the system before
and after ball X impacts with balls Yand Z is conserved.
A 1,2
B 1,3
C 3
D 1,2,3
WHAT IS THE ANS??@@ WITH EXPALIN PLS><
更新1:
即是話 apply The Law of Momentum Conservation 時 impact 的 direction 要一樣??
