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: hiarker (srh959) homework 28 Turner (58220) 1 This printout should have 11 questions. Multiplechoice questions may continue on the next column or page find all choices before answering. 001 10.0 points A solid sphere of radius R and mass m is held against a wall by a string being pulled at an angle . W P F R Determine the torque equation about the point P. 1. mg R = F R 2. mg R = 2 F R 3. mg R = F (1 cos ) R 4. mg R = F (1 + cos ) R 5. mg R = F (1 sin ) R 6. mg R = F (1 + sin ) R correct Explanation: W P F R R ( 1 + s i n ) A The clockwise torque about point P is CW = AP F = R (1 + sin ) F and the counterclockwise torque is CCW = mg R . From rotational equilibrium, CCW = CW mg R = R (1 + sin ) F . 002 (part 1 of 2) 10.0 points A solid sphere of radius R and mass M is placed in a wedge as shown in the figure. The inner surfaces of the wedge are frictionless. M R A B hiarker (srh959) homework 28 Turner (58220) 2 Determine the force exerted by the wedge on the sphere at the left contact point. 1. F A = 2 M g sin sin( + ) 2. F A = M g cos cos( + ) 3. F A = M g sin sin( + ) 4. F B = M g cos cos( + ) 5. F A = M g cos sin( + ) correct 6. F A = M g sin cos( + ) Explanation: Mg A B F A F A cos F B F B cos F A sin F B sin At equilibrium, summationdisplay vector F = 0 summationdisplay vector = 0 . Call the normal forces F A and F B . They make angles and with the vertical, so applying translational rotation horizontally summationdisplay F x = 0 F A cos  F B cos = 0 F B = F A cos cos , and vertically summationdisplay F y = 0 F A sin  M g + F B sin = 0 F A sin + F A sin cos cos...
View
Full
Document
This note was uploaded on 04/23/2010 for the course PHY 303K taught by Professor Nui during the Spring '09 term at University of TexasTyler.
 Spring '09
 NUI
 Physics, Mass, Work

Click to edit the document details