PHYSICS 1306, QUIZ 4
Chapter 8
August 4, 2003
Partial credit will be LIBERAL, provided that you show your work!
USE BACK IF NECESSARY!
Name: ______________________ Social Security Number ______________________
1. (10 points) CONCEPTUAL QUESTIONS
Answer briefly, in complete, grammatically correct English sentences. You may supplement your answers with equations, but keep these to a minimum and explain what the symbols mean!!
a. Define: Torque, Rotational Kinetic Energy, Angular Momentum.
b. State Newton’s 2nd Law for Rotational Motion. Explain the meaning of any symbols you use! (Note: The answer F = ma will receive ZERO credit!)
2. (20 points) See figure. A large pulley wheel has radius R = 0.25 m and mass M = 30 kg. Assume that it may be treated as a solid disk so that the moment of inertia, I = MR2, is valid. Neglect friction between the wheel and its axle. A cord is wrapped around the wheel
and pulled with a tangential force FT, as shown. Starting from rest, the wheel is observed
to reach an angular speed of = 35 rad/s after 5 s. Compute the following:
a. The linear velocity v and the radial acceleration aR of a point on the rim after 5 s.
b. The angular acceleration of the wheel and the tangential acceleration atan of a point on the rim.
c. The net torque on the wheel and the force FT required to produce this torque.
d. The rotational kinetic energy and angular momentum of the wheel after 5s.