Finding the force overcoming friction

[sarahhhh]

Homework Statement

There are two ways to find how much work is done overcoming friction. Please describe both methods.

Homework Equations

Wf = Ff x d

The Attempt at a Solution

I know one method-- you have you know the force overcoming friction. You would use (Wf = Ff x d). But i really cannot figure out the calculation that can be done to find wasted work. can someone PLEASE help me?! thank you so much!

 

[sarahhhh]

please help! :(