Conserv. of E and Work momentum

[saliiravezz]

Homework Statement

suppose the rlller coaster in the figure passes point 1 with a speed of 1.70m/s. If the average force of friction is equal to 1/5th of its weight, with what speed will it reach point 2? the distance traveled is 45m.

Homework Equations

conserv. of E
and Work

The Attempt at a Solution

- i don't know how to do it.

 

[bp_psy]

You start by writing the energy equation.