help!! physics again...?

Question

please solve this using the law of conservation of momentum...



a 0.02 kg ball moving to the right at 0.25m/s makes an elastic head on collission with a 0.04kg ball moving to the left at 0.15m/s after the collission, the smaller ball moves to the left at 0.16m/s. what is the velocity of the 0.04kg ball after collission?


please with solution...use the law of conservation of momentum...thanks

Answer 1

use sign convention method

for left -ve
for right +ve

Answer 2

(.02)(.25) + (.04)(-.15) = (.02)(-.16) + (.02)()
.005 -.006 = -.0032 + .02x
-.001 +0032 = .02x
.22 = .11m/s to the right

I think...