Ball A of mass 0.1 kg is dropped from rest from a certain height. Ball B of mass 0.2 kg is dropped from rest from the same height. Ignoring air resistance, which of the following will be different for these two balls?
(A) impact speed with the ground (C) magnitude of momentum at impact with the ground
(B) time to fall to the ground (D) acceleration during the fall

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.