Answer:
forces that are equal in size and opposite in direction. Balanced forces do not result in any change in motion. unbalanced. forces: forces applied to an object in opposite directions that are not equal in size. Unbalanced forces result in a change in motion.

hope helpful ~
Explanation: (I think)
Plug your values into the momentum equation.
So m1= 63kg
m2 = 10 kg
V1 = 12 m/s
And then plug in your values and solve for your unknown (v2)
The thin layer of water that covers most earths surface is called the hydrosphere.