A 0.110-kg ball (ball x) moving at 1.20 m/s to the right, collides head-on with an identical ball (ball Y) moving to the left at a velocity of 0.600 m/s. Ball Y rebounds and reverses direction at a velocity of 0.800 m/s. What is the velocity of ball X following the collision? A 0.200 m/s to the left
B. 0.0924 m/s to the right
C. 0.0880 m/s to the right
D. 0.00440 m/s to the left​

answer: the potential energy decreases from 379 j to 243 j

explanation:

for the law of conservation of energy, the total energy in a system must be conserved. the total energy of the system is given by the sum of kinetic (k) and potential (u) energy:

e = k + u

the total energy is e=675 j, and this does not change.

initially, the kinetic energy is k=296 j, so the potential energy is

at the end, the kinetic energy is k=432 j, so the potential energy is

so, we see that the potential energy has decreased from 379 j to 243 j.