What is the average coefficient of static friction on the track during a roller coaster ride during a drop? Assume the length of the drop is the height of the drop, and the energy loss in the system is entirely friction. Also assume the g force is 4g when dropping.

Given:

d = 74.7 m

V_i = 0 m/s

V_f = 130 km/hr

Mass of roller coaster: 5500 kg