Idk how to calculate the net velocity? Is it that I just need to subtract those since they are in opposite directions? or do i need still need to consider about the given volume & density values??

hi

the balls stick together so it is an inelastic collision and we use the formula:

m1v1 + m2v2 = (m1+m2)v’

density = m/v

since the balls have the same volume and density A = 2 * density B, then mA = 2mB

i will use mA = 2m and mB = m

2m * 6 - m * 3 = (m+2m)v’

(notice the sign of the momentum for B is negative because it is moving in the opposite direction to A)

12m - 3m = 3mv’

9m=3mv’

3=v’ to the right

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