PP A Simple Solution for a Stuck Car If your car is stuck in the mud and you don’t have a winch to pull it out, you can use a piece of rope and a tree to do the trick. First, you tie one end of the rope to your car and the other to a tree, then pull as hard as you can on the middle of the rope, as shown in Figure P4.68a. This technique applies a force to the car much larger than the force that you can apply directly. To see why the car experiences such a large force, look at the forces acting on the center point of the rope, as shown in Figure P4.68b. The sum of the forces is zero, thus the tension is much greater than the force you apply. It is this tension force that acts on the car and, with luck, pulls it free. The sum of the three forces acting on the center point of the rope is assumed to be zero because A. This point has a very small mass. B. Tension forces in a rope always cancel. C. This point is not accelerating. D. The angle of deflection is very small.
Step 1 of 3 According to newton's second law The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object. In the above case , more forces acting on the car than the middle of the rope where you going to pull si this is the reason car will not accelerate due to awe are applying small force rather than car force so there is no acceleration Step 2 of 3 When there is no acceleration means body will remain at rest and net force acting on the body or sum of forces acting on the body is Zero Then we have newton’s second law I.e F=ma When acceleration is zero F=0 Means the centre of the rope is not accelerating so option © is correct