This preview shows pages 1–3. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: alexander (jra2623) homework 23 Turner (92510) 1 This printout should have 11 questions. Multiplechoice questions may continue on the next column or page find all choices before answering. 001 (part 1 of 3) 10.0 points A mobile consists of four weights hanging on three horizontal rods of negligible mass. 20 N W 1 W 2 W 3 4 m 9 m 6 m 5 m 5 m 4 m Find the unknown weight on the lower rod. Correct answer: 8 . 88889 N. Explanation: Let : W = 20 N , r 1 = 9 m , and l 1 = 4 m . Applying rotational equilibrium about an axis through the point of suspension of the lowest rod in the mobile, summationdisplay vector = l 1 W  r 1 W 1 = 0 W 1 = l 1 W r 1 = (4 m) (20 N) 9 m = 8 . 88889 N . 002 (part 2 of 3) 10.0 points Find the unknown weight on the middle rod. Correct answer: 24 . 0741 N. Explanation: Let : r 2 = 5 m and l 2 = 6 m . Applying rotational equilibrium about an axis through the point of suspension of the middle rod in the mobile, summationdisplay vector = l w W 2 r 2 ( W + W 1 ) = 0 W 2 = r 2 ( W + W 1 ) l w = (5 m) (20 N + 8 . 88889 N) 6 m = 24 . 0741 N . 003 (part 3 of 3) 10.0 points Find the unknown weight on the upper rod. Correct answer: 66 . 2037 N. Explanation: Let : r 3 = 4 m and l 3 = 5 m . Applying rotational equilibrium about an axis through the point of suspension of the top rod in the mobile, summationdisplay vector = l e ( W + W 1 + W 2 ) r 3 W 3 = 0 W 3 = l 3 ( W + W 1 + W 2 ) r 3 = 5 m 4 m (20 N + 8 . 88889 N +24 . 0741 N) = 66 . 2037 N . 004 10.0 points The angle of the inclination is 36 . 6 , the outer part of the large pulley has a radius of 3 r and alexander (jra2623) homework 23 Turner (92510) 2 the inner part of the large pulley has a radius...
View
Full
Document
This note was uploaded on 10/20/2011 for the course PHY 302K taught by Professor Kaplunovsky during the Summer '08 term at University of Texas at Austin.
 Summer '08
 Kaplunovsky
 Work

Click to edit the document details