CP? A 2.00-kg textbook rests on a frictionless, horizontal surface. A cord attached to the book passes over a pulley whose diameter is 0.150 m, to a hanging book with mass 3.00 kg. The system is released from rest, and the books are observed to move 1.20 m in 0.800 s. (a) What is the tension in each part of the cord? (b) What is the moment of inertia of the pulley about its rotation axis?
Solution 13E Introduction Book and the mass will move with equal and constant acceleration as they are connected by string. Knowing the distance travelled in given time we can calculate the acceleration. Now using this acceleration we can calculate the forces acting on each of them and from that we can calculate the tension of the rope. Again using the tension, mass and acceleration we can calculate the moment of inertia of the pulley. Step 1 Since the book moved 1.20 m in 0.800 s, starting from rest, the acceleration of the book is given by Step 2 Let us first see the free body diagram of the block and the hanging mass. For the book And for the hanging mass Since the book is on frictionless horizontal table, only horizontal force acting on the book is the tension of the string. Hence the force acting on the book si Hence the tension of the string in the book side is 7.50 N. Now on the hanging mass side we can say that Hence the tension on the hanging mass side is 18.1 N.