1. A cart on wheels weighs 2400 N. The coefficient of rolling friction between the wheels and floor is 0.16. What force is needed to keep the cart rolling uniformly?
2. A wooden crate weighs 780 lb. What force is needed to start the crate sliding on a wooden floor when the coefficient of static friction is 0.40?
3. A piano weighs 4700 N. What force is needed to start the piano rolling across the floor when the coefficient of static friction is 0.23?
4. A force of 850 N is needed to keep the piano in Problem 3 rolling uniformly. What is the coefficient of rolling friction?
5. A dog sled weighing 750 lb is pulled over level snow at a uniform speed by a dog team exerting a force of 60 lb. Find the coefficient of friction.
6. A horizontal conveyor belt system has a coefficient of kinetic friction of 0.65. The motor driving the system can deliver a maximum force of 2.5 x 106 N. What maximum total weight can be placed on the conveyor system?
7. A tow truck can deliver 2500 lb of pulling force. What is the maximum-weight truck that can be pulled by the tow truck if the coefficient of rolling friction of the truck is 0.10?