Tiger Ale

How do you use the law of logarithms to calculate for u^c=(a^r)^c?

A bungee jumper of mass of 60.0 kg falls off a bridge with zero initial velocity. The bridge is 50.0 m above the river. When the cord is stretched at its maximum (position B), the cord stores 10.0 kJ of elastic potential energy. Neglect air friction. (a)E...