1. A weight of 30lb rests on an inclined plane 3 ft high and 5 ft long. a force F making an angle of 30° with the plane pulls the body upward. If the coefficient of friction is 0.20, how much force is necessary to maintain uniform motion upward?
2. A board is 8 ft long. how high will one end be raised so that a block on it will just begin to slide down if the coefficient of friction is 0.30?