Question from our Lab today on Friction

[Husker70]

Homework Statement

Assuming that f=mu(N), show that the cofficient of (rolling) friction for the
car moving down the inclined plane with a constant speed is given by
mu=tan(theta) - m2/mc cos(theta)(Use symbols, not numbers.)

Homework Equations

The Attempt at a Solution

Can someone explain any of this so I can understand what they are asking.
I can't get started because I don't really understand it.
Thanks,
Kevin

 

[tiny-tim]

rolling

Hi Kevin!

(have a mu: µ and a theta: θ )

Assuming that f=mu(N), show that the cofficient of (rolling) friction for the
car moving down the inclined plane with a constant speed is given by
mu=tan(theta) - m2/mc cos(theta)(Use symbols, not numbers.)
…
Can someone explain any of this so I can understand what they are asking.
I can't get started because I don't really understand it.

hmm … fair point!

I wish professors would explain rolling more carefully.

Before I go any further, can you say what m2 and mc are (I can guess what θ is ), and show us a bit more of the question?