Physics Problem Sets

ZPH 123 Problem set Forces 1. Two 25.0-N weights are suspended at opposite ends of a rope that passes over a light, frictionless pulley. The pulley is attached to a chain that goes to the ceiling. a. What is the tension in the rope? b. What is the tension in the chain? 2. A stockroom worker pushes a box with mass 11.2 kg on a horizontal surface with constant speed of 3.50 m/s. The coefficient of kinetic friction between the box and the surface is 0.20. a. What horizontal force must be applied by the worker to maintain the motion? b. If the force calculated in part a is removed, how far does the box slide before coming to rest? 3. 4. In physics lab experiment, a 6.00-kgbox is pushed across a flat table by a horizontal force F. a. If the box is moving at a constant speed of 0.350 m/s and the coefficient of kinetic friction is 0.12, what is the magnitude of F? b. What is the magnitude of F if the box is speeding up with a constant acceleration of 0.180 m/s2? c. How would your answers to parts a and b change if the experiments were performed on the moon, where g = 1.62 m/s2? 4. A light rope is attached to a block with mass of 4.00 kg that rests on a horizontal, frictionless surface. The horizontal rope passes over a frictionless, massless pulley and a block of mass m is suspended from the other end. When the blocks are released, the tension in the rope is 10.0 N. a. What is the acceleration of either block? b. What is the mass m of the hanging block? c. How does the tension compare to the weight of the hanging block? 5. A large wrecking ball (Figure 1) is held in place by two light steel cables. If the mass m of the wrecking ball is 4090 kg, what is: O a. The tension TB in the cable that makes an angle of 40 with the vertical? b. The tension TA in the horizontal cable? 6. 3. An adventurous archaeologist (figure 2) crosses between two rock cliffs by slowly going hand-over-hand along a rope stretched between the cliffs. He stops to rest at the middle of the rope. The