Ch10 HW3 S2008

# Ch10 HW3 S2008 - Ch10 HW3 S2008 4/25/08 10:34 AM Web Assign...

This preview shows pages 1–4. Sign up to view the full content.

4/25/08 10:34 AM Ch10 HW3 S2008 Page 1 of 11 http://www.webassign.net/v4cgikseiloff3@gatech/student.pl?t=20080425142815kseiloff3@gatech1286165155 Ch10 HW3 S2008 (Homework) KRISTIN SEILOFF Instructor: Jennifer Curtis Description Torque; Angular impulse; Systems with zero torque Instructions Reading: Section 10.3-10.7 In this assignment you may submit each question part separately. Three submissions are allowed for numerical answers, and two submissions for multiple choice answers. Web Assign Current Score: 50 out of 61 Due: Monday, April 7, 200808:35 AM EDT 1. 4/4 points As shown in the diagram below, seven forces all with magnitude | | = 33 N are applied to an irregularly shaped object. Each force is applied at a different location on the object, indicated by the tail of the arrow; the directions of the forces differ. The distances shown in the diagram have these values: w = 15 m, h = 24 m, and d = 23 m. For each force, calculate the z component of the torque due to that force, relative to location A (x to the right, y up, z out of the page). Make sure you give the correct sign. (1) A,1,z = -792 -792 N · m (2) A,2,z = -792 -792

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
4/25/08 10:34 AM Ch10 HW3 S2008 Page 2 of 11 http://www.webassign.net/v4cgikseiloff3@gatech/student.pl?t=20080425142815kseiloff3@gatech1286165155 N · m (3) A,3,z = -792 -792 N · m (4) A,4,z = -495 -495 N · m (5) A,5,z = 0 0 N · m (6) A,6,z = 0 0 N · m (7) A,7,z = 759 759 N · m Relative to location A , what is the z component of the net torque acting on this object? A,net,z = -2112 -2110 N · m Solution or Explanation The magnitude of the torque is r | |, and the sign of the z component is determined using the right-hand rule. 2. 7.5/7.5 points A uniform solid disk with radius 9 cm has mass 0.9 kg (moment of inertia I = ½ MR 2 ). A constant force 12 N is applied as shown. At the instant shown, the angular velocity of the disk is 25 radians/s in the direction (where + x is to the right, + y is up, and + z is out of the page, toward you). The length of the string d is 19 cm. At this instant, what are the magnitude and direction of the angular momentum about the center of the disk? = .0911 0.0911 kg·m 2 /s Direction: -z -z
4/25/08 10:34 AM Ch10 HW3 S2008 Page 3 of 11 http://www.webassign.net/v4cgikseiloff3@gatech/student.pl?t=20080425142815kseiloff3@gatech1286165155 What are the magnitude and direction of the torque on the disk, about the center of mass of the disk? = 1.08 1.08 N · m Direction: -z -z The string is pulled for 0.2 s. What are the magnitude and direction of the angular impulse applied to the disk during this time? = .216 0.216 N · m · s Direction: -z -z After the torque has been applied for 0.2 s, what are the magnitude and direction of the angular momentum about the center of the disk? .3071

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

## This note was uploaded on 10/19/2009 for the course PHYSICS 2211M taught by Professor Schatz during the Spring '06 term at Georgia Institute of Technology.

### Page1 / 11

Ch10 HW3 S2008 - Ch10 HW3 S2008 4/25/08 10:34 AM Web Assign...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online