Question

a 2-kg metal ball moving at a speed of 3 m/s strikes a 1-kg wooden ball that is at rest. after the collision, the speed of the metal ball is 1 m/s. Assuming momentum is conserved, what is the speed of the wooden ball

Answer 1

The momentum equation is p=m*v Where m=mass and v=velocity respectively. since momentum is conserved you can assume p initial=p final. so to find p initial you need to get the momentum of both balls before the collision.

m*v(metal ball)+m*v(wooden ball)=p
2*3+1*0=p
6=p

so then p final should also = 6
set the same equation = 6 but use your given speed of after the collision

m*v(metal ball)+m*v(wooden ball)=p
2*1+1*X=6
2+X=6
X=4

So then the speed would be 4 m/s

Hope this helps