centripetal acceleration is given by formula

given that


now we have




so the ratationa frequency is given by




Answer:
Subtract the kinetic energy at the bottom from the potential energy loss. The remainder becomes frictional heat.
Potential energy loss:
M g H = 21.7*9.81*3.5 = 745.1 J
Kinetic energy at bottom of slide:
= (1/2) M v^2 = 52.5 J
I only know what number 1. is and its Mechanical Energy.