PROBLEMS FROM FISHBANE
                               
                         JUNE 13 - JUNE 18
        
        CHAPTER 9
        45. A wheel of radius 24.6 cm whose axis is fixed starts
            from rest and reaches an angular velocity of 4.15 rad/s
            in 2.68 s due to a force of 13.4 N acting tangentially
            on the rim.  (a) What is the rotational inertia of the
            wheel?  (b) What is the change in the angular momentum
            during the 2.68 s?  (c) How many revolutions does the
            wheel make?  (d) How much rotational kinetic energy 
            does the wheel have after 2.68 s?

        CHAPTER 10
        13. A square, 20 cm on the side, is made of very light 
            sticks.  Four identical masses of m = 0.1 kg form the 
            corners of the square.   The square rotates with an
            angular velocity of 8 rad/s about an axis perpendicular
            to its plane through the center of the square.
            (a) Calculate the rotational inertia of the system
            about the rotation axis and use it to find the angular
            momentum about this axis.  (b) Use the general 
            definition of angular momentum to calculate the
            angular momentum of each mass with respect to the
            center of the square, and add these up.  Compare the
            results of (a) and (b).