One kilogram of a contaminant, denoted as M, is spilled at a point ina 4m deep reservoir, denoted as L, and is instantaneously mixed over the entire depth.

a. If the diffusion coefficients in the N-S (Dy) and E-W (Dx) directions are 5 m^2/s and 10 m^2/s, respectively, calculate the concentration as a function of time at locations 100m north and 100m east of the spill; that is, find an expression for C(t) at location point (x, y)=(100m, 100m).
b. What is the concentration at the spill location after 5 minutes?

Aflywheel accelerates for 5 seconds at 2 rad/s2 from a speed of 20 rpm. determine the total number of revolutions of the flywheel during the period of its acceleration. a.5.65 b.8.43 c. 723 d.6.86

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?

The proportional limit is always greater than the yield strength for a material. a)-trune b)- false