EGR 283 Quiz #4 Solutions


All results must be given to the precision used in the textbook.  Assume that the data are known to the same precision.  Thus, when a value of 2 kips is given, it is assumed that it is known to 3 digits; i.e., 2.00 kips.  You may receive partial credit if you show your work (on the reverse).  The units requested must be given with all answers. Print this page and write the answers in the blanks.  Sign the statement at the bottom.  Then submit the page before class on Monday.

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1. A shaft rotates at 450 rpm and delivers power of 35 hp.  What torque acts on the shaft?  Give your answer in kN-m. 4.90 kN-m
2. The stepped shaft of Problem 3.89 has an overall allowable stress of 6000 psi.  What must the maximum allowable stress at the surface of the smaller portion of the shaft be if the fillet radius is 0.3125 in? 5000 psi
3. For Problem 4.2, determine the moment of inertia of the cross section about the neutral axis in mm4. 8.59 x 104 mm4
4. The cross section of a beam is 140 mm x 140 mm.  Under load, it is found that the normal stress due to bending is 40 MPa in tension on the bottom and 40 MPa in compression on the top.  What is the bending moment in kN-m? 18.29 kN-m
5. True or False?  For a beam made of two materials of different elastic moduli, the neutral axis passes through the centroid of the composite section. (circle one) False
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