# Physics

posted by
**Justin**
.

*I am lost on a bunch of different problems, and this is one of them. Please note that I am NOT asking for final answers, just some guidance so that I can figure out how to do the problem!!! I know that a lot of times on this site it is commented that we are fishing for answers, but I just need some guidance on some stuff I honestly cannot figure out how to do, no matter how easy it might seem to others.

While a roofer is working on a roof that slants at 40.0 degrees above the horizontal, he accidentally nudges his 85.0 N toolbox, causing it to start sliding downward, starting from rest.

If it starts 5.00 m from the lower edge of the roof, how fast will the toolbox be moving just as it reaches the edge of the roof if the kinetic friction force on it is 22.0 N?

Answer expressed in m/s.

Take the toolbox weight, break it into two components, normal and down the roof. Then right the force equation

net force= mass*acceleration

forcedown - friction = mass*acceleration.

solve for acceleration. Then,

Vf= sqrt (2*acceleration*distance)