University:
Michigan State University
Course:
ERG 160 | Success in Science, Technology, Engineering, and Mathematics
Academic year:

2021
Views:

148

Pages:

1
Author:

teespagmaxrtf

COSMOS: Complete Online Solutions Manual Organization System Chapter 8, Solution 87. It is convenient to replace the ( 66 kg ) g and ( 24 kg ) g weights with a single weight of ( 90 kg )( 9.81 N/kg ) = 882.9 N, (1.8 m )( 24 kg ) − ( 0.15 m )( 66 kg ) located at a distance x = 90 kg = 0.04 m to the right of B. FBD pulley + gate: ( rf = rs sin φs = rs sin tan −1 µ s ) * ( = ( 0.012 m ) sin tan −1 0.2 ) rf = 0.0023534 m α = tan −1 β = sin −1 rf OB = sin −1 0.04 m = 14.931° 0.15 m OB = 0.0023534 m = 0.8686° 0.15524 m 0.15 m = 0.15524 m cos α then θ = α − β = 14.062° P = W tan θ = 221.1 N P = 221 N ! NOTE FOR PROBLEMS 8.75–8.89 ( ) Note to instructors: In this manual, the simplification sin tan −1 µ ≈ µ is NOT used in the solution of journal bearing and axle friction problems. While this approximation may be valid for very small values of µ , there is little if any reason to use it, and the error may be significant. For example, in Problems 8.76–8.79, µ s = 0.50, and the error made by using the approximation is about 11.8%. Vector Mechanics for Engineers: Statics and Dynamics, 8/e, Ferdinand P. Beer, E. Russell Johnston, Jr., Elliot R. Eisenberg, William E. Clausen, David Mazurek, Phillip J. Cornwell © 2007 The McGraw-Hill Companies.