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 1 1. 2 keg 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 goes the box slide before coming to rest? . 4. In physics lab experiment, a 6. 00-kabob 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/so? C. How would your answers to parts a and b change if the experiments were performed on the moon, where g = 1. 62 m/so? 4. A light rope is attached to a block with mass of 4. 00 keg that rests on a horizontal, frictionless surface.

The horizontal rope passes over a frictionless, measles’s 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 keg, what is: O a. The tension TUB 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 rope will break if the tension if the tension in it exceeds 2. 5 x 104 N, and our hero’s mass is 90. 0 keg. O a. If the angle B is 10. 0 , find the tension in the rope. B. What is the smallest value the angle B can have if the rope is not to break? Figure 2 6. Two crates connected by a rope lie on a horizontal surface. Crate A has mass ma and crate B has mass MBA. The coefficient of kinetic friction between each crate and the surface is PC.

The crates are pulled to the right at constant velocity by a horizontal force F. In terms of ma, MBA and PC, calculate: a. The magnitude of the force F. B. The tension in the rope connecting the blocks. 7. Blocks A, B and C (figure 3)are placed as shown in the diagram below, and connected by ropes of negligible mass. Both A and B weigh 25. 0 N each and the coefficient of the kinetic friction between each block and the surface is 0. 35. Block C descends with constant velocity. A. Find the tension in the rope connecting blocks A and B. B. What is the weight of block C? Figure 3 Figure 1 Physics Problem Sets By Aerographical