Question

hectures Of 10.5 Cheder/ Homework: HW11: Parallel Axis Theorem And Torque & Rotational Dynamics Opcion Rotating Cylinder Score Thred Asmall, solid cylinder with mass and radius om starts froen rest and rotates without friction about an als through its center of mass. The rotation and is feed so that the center of mass of the cylinder does not move as the cylinder rotates. A string is wrapped around the circunference of the cylinder and is pulled using a constant force F N Exam Pra Option Exam Pra - Optio fixed axis Tipler 1) Which of the following statements is true! Rotator There is a non-zero net force on the cylinder, but the net torque on the cylinder is zero There is a non-zero net torque on the cylinder, but the net force on the cylinder is zero. There is both a non-zero net torque and a non-zero net force on the cylinder Both the net torque and net force on the cylinder are zero. Submit Rotato Conces 2) The cylinder will undergo Rotati linear acceleration but not angular acceleration. angular acceleration but not linear acceleration both linear and angular acceleration neither linear nor angular acceleration Submit Three 3) What is the moment of inertia of the cylinder kg m Submit 4) What is the magnitude of the torque on the cylinder from the force due to the string! Nm Submit e to search

Answer 1

1) b) There is a non zero net torque on the cyllinder, but the net force on the cyllinder is zero.

2) b) angular acceleration but not linear acceleration.

3) I = (1/2)*M*R^2

= (1/2)*3*0.03^2

= 1.35*10^-3 kg.m^2

4) Torque = F*r

= 4*0.03

= 0.12 N.m

5) angular acceleration, alfa = torque/I

= 0.12/(1.35*10^-3)

= 88.9 rad/s^2

6) w = wo + alfa*t

= 0 + 88.9*7

= 622 rad/s

7) Work done = gain in kinetic energy

= (1/2)*I*w^2

= (1/2)*1.35*10^-3*622^2

= 261 J

8) b) w_new = 2*w