Question

A block of mass 7.50 kg is observed at rest on a 25.0° slope. From this observation, what can be concluded about the friction coefficient between the block and the surface of the slope?

Answer 1

The force of friction is, in this case, large enough to overcome the downward force of gravity, since the block does not move down the slope. We can say that the force of friction (and by extension, the friction coefficient) is *at least* as large as a particular value.

As for how to calculate this value... I think you would want to compare it to the force of gravity that is acting on the block, based on the mass of the block and angle of the slope. You might be able to get some guidance on the exact process of how to do that