I haven't even taken physics, but I'll take a shot. If it's at equilibrium, I assume that means that it isn't moving. This means that its acceleration is zero, so the net force is zero. This means that F is force pushing it up the hill, which is equal in magnitude to the force down the hill. The force down the hill is equal to the force of gravity minus the friction. You would then have to figure out the force of gravity, knowing that the slope is 60 degrees and a straight fall would be 90 degrees. The mass is 2 kg, and the acceleration is 9.8m/s,/s, so the force would be 19.6. Then I think you need to multiply by 60/90 or 2/3, which would get you about 13.1. Subtract the .3 from friction and F would be about 12.8 (I'm not sure what the unit is.) If this is wrong, it's because I haven't taken physics and I'm pretty much guessing. However, if this is right, then this problem isn't very hard and you probably need to pay more attention in class. EDIT: because acceleration is quadratic, maybe the correction for the angle should be 3600/8100, or 4/9. This would make the force of gravity 8.7, subtract the friction and F = 8.4. Or, if you square after the division, this would be 2/9, making the force of gravity 4.4, making F = 4.1. Again, I have no idea if this is correct or not. I might be missing some sort of constant.