1. The problem statement, all variables and given/known data A constant speed conveyor belt delivers stones and drops them in a bin as shown. The conveyor ends with a pulley with a 100 mm radius. The coefficients of friction on the belt are μs = 0.20 and μk = 0. If the velocity of the pulley is 0.1 m/s, what is the angle,theta, at which the stones fall off the belt? 3. The attempt at a solution I am kinda lost on this question, it says "when the stone falls off the belt" so I am guessing at this moment the normal force is 0? I also don't think there is any tangential acceleration, but I think there would be normal acceleration. If there is no normal force when the stone falls off the rock, would there then be no friction? This is what I got using this method, which doesn't seem possible. I drew a FBD and got the equation mgCos(theta) = m(v^2/r), the m's will cancel and your left with gCos(theta) = v^2/r, solving for theta you get 89.42 degrees, which seems much too large.