ADDITIONS TO HRW PROBLEMS AND PROBLEMS FROM OTHER TEXTS JUNE 18 - JUNE 24 HRW - CHAPTER 11 58. You must do problem 58 twice, once using Newton's Laws, and once using Conservation of Energy. So add parts (c) and (d), in which you use Newton's Laws instead of Energy Conservation to do exactly the same problem as in (a) and (b). Fishbane - 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? Fishbane - 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). PROBLEM G2 A metal ball is to be rolled down a track inclined at an angle theta with respect to the horizontal, starting from rest. The track is a pair of rails, with the separation distance between the two rails equal to the radius of the ball. (a) Find the acceleration of the ball after it is released. (b) Find a_x the horizontal component of the acceleration of the ball after it is released. (c) Find the angle theta for which a_x is a maximum.