41.Three identical 6.0-kg cubes are placed on a horizontal frictionless surface in contact with one another. The cubes are lined up from left to right and a force is applied to the left side of the left cube causing all three cubes to accelerate to the right at 2.0 m/s2. What is the magnitude of the force exerted on the right cube by the middle cube in this case?a. 12 Nb. 24 Nc. 36 Nd. none of the above42.A sled weighs 100 N. It is held in place on a frictionless 20° slope by a rope attached to a stake at the top; the rope is parallel to the slope. Find the tension in the rope.43.A sled weighs 100 N. It is held in place on a frictionless 20° slope by a rope attached to a stake at the top; the rope is parallel to the slope.What is the normal force of the slope acting on the sled?46

Chapter 4, The Laws of Motion44.A 500-N tightrope walker stands at the center of the rope such that each half of the rope makes an angle of 10.0° with the horizontal. What is the tension in the rope?45.A 500-N tightrope walker stands at the center of the rope. If the rope can withstand a tension of 1 800 N without breaking, what is the minimum angle the rope can make with the horizontal?a. 4°b. 8°c. 10°d. 15°46.A 20kg traffic light hangs midway on a cable between two poles 40 meters apart. If the sag inthe cable is 0.40 meters, what is the tension in each side of the cable?47.A girl is using a rope to pull a box that weighs 300 N across a level surface with constant velocity. The rope makes an angle of 30° above the horizontal, and the tension in the rope is 100 N. What is the normal force of the floor on the box?48. A karate master strikes a board with an initial velocity of 10.0 m/s, decreasing to 1.0 m/s as his hand passes through the board. If the time of contact with the board is 0.002 0 s, and the mass of the coordinated hand and arm is 1.0 kg, what is the force exerted on the board?47

Chapter 4, The Laws of Motion49.Find the tension in an elevator cable if the 1 000-kg elevator is descending with an acceleration of 1.8 m/s2, downward.a. 5 700 Nb. 8 000 Nc. 9 800 Nd. 11 600 N4.6 Forces of Friction50. A block of mass 5.00 kg rests on a horizontal surface where the coefficient of kinetic friction between the two is 0.200. A string attached to the block is pulled horizontally, resulting in a 2.00-m/s2acceleration by the block. Find the tension in the string. (g= 9.80 m/s2)

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