So I was watching some of those physics videos posted in schoolwork board, and although he probably didn't make an error here, I don't think I understand it.
Here's the pictues. I'll elaborate after it so you guys know what I'm talking about...
A 30.0 kg box sliding at 5.00 m/s on a rough surface is brought to rest by 20.0 N of friction. What distance does the box slide?
KE = 1/2*m*(v^2-v^2)
The Attempt at a Solution
I know that the change in velocity is 5.00 m/s since it is going to...