To determine shear stress and shear stress distribution developed in circular shafts subjected to applied torque. prior to starting this tutorial, students should be familiar with: the torsion formula; equations for calculating the polar moment of inertia for circular cross-sections; and how to find internal torque in a statically determinate system. the solid shaft cross-sections shown are subjected to the externally applied torques shown. compare the corresponding shear stresses developed in each shaft at point p. rank the solid shafts from the largest shear stress at p to the smallest shear stress at p. (for example, 4 > 3 = 1 > 2). the correct ranking cannot be determined.

A3-mm-thick panel of aluminum alloy (k 177 w/m-k, c 875 j/kg-k and ? = 2770 kg/m) is finished on both sides with an epoxy coating that must be cured at or above t,-150°c for at least 5 min. the production line for the curing operation involves two steps: (1) heating in a large oven with air at ts,0-175°c and a convection coefficient of h, 40 w/m2. k, and (2) cooling in a large chamber with air at 25°c and a con- vection coefficient of he 10 w/m2.k. the heating portion of the process is conducted over a time interval te which exceeds the ime required to reach 150°c by 5 min (h = r + 300 s). the coating has an emissivity of ? = 0.8, and the temperatures of the oven and chamber walls are 175 and 25°c, respectively. if the panel is placed in the oven at an initial temperature of 25°c and removed from the chamber at a safe-to-touch tempera ture of 37°c, what is the total elapsed time for the two-step curing operation?