2.9. EXERCISES 29

11. A car is stuck in the mud. There is a cable stretched tightly from this car to a treewhich is 20 feet long. A person grasps the cable in the middle and pulls with a forceof 100 pounds perpendicular to the stretched cable. The center of the cable movestwo feet and remains still. What is the tension in the cable? The tension in the cableis the force exerted on this point by the part of the cable nearer the car as well as theforce exerted on this point by the part of the cable nearer the tree.