I am currently working on a problem that I do not know how to solve. It is on the Work-Energy theorem. I would really appreciate it if you could help. :D Kinetic Energy = 1/2 mv^2 Potential Energy = mgh Work = Fd KE(initial) + PE(initial) = KE(final) + PE(final) The height above the ground of a child on a swing varies from 50 cm at the lowest point to 200 cm at the highest point. The maximum speed of the child is? A. about 5.4 m/s B. about 7.7 m/s C. about 29 m/s D. dependent on the child's mass The answer for this question is A, and I do not understand how they got it. I also have one more question. The 2.0-kg head of an ax is moving at 60 m/s when it strikes the log. If the blade of the ax penetrates 20 mm into the log, the average force it exerts is A. 3 kN B. 90 kN C. 72 kN D. 180 kN The answer is 180 kN. I have no idea where to start for these problems. Help would really be appreciated!