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?

The short distance from the objective lens to the object causes problems at high magnification. which of the following is the most serious? a. cleaning the object surface b. positioning the object c. reflection from the object surface. d. illumination of the object

What is the chief metrological difference between measuring with a microscope and with an electronic comparator? a. the microscope is limited to small workpieces.a. the microscope is limited to small workpieces. c. the comparator can only examine one point on the workpiece. d. the microscope carries its own standard.

Liquid flows at steady state at a rate of 2 lb/'s through a pump, which operates to raise the elevation of the liquid 100 ft from control volume inlet to exit. the liquid specific enthalpy at the inlet is 40.09 btu/lb and at the exit is 40.94 btub. the pump requires 3 btu/s of power to operate. if kinetic energy effects are negligible and gravitational acceleration is 32.174 tt/s, the heat transfer rate associated with this steady state process is most closely 1)-2,02 btu/s from the liquid to the surroundings 2)-3.98 btu/s from the surroundings to the liquid. 3)-4.96 btu/s from the surroundings to the liquid. 4)-1.04 btu/s from the liquid to the surroundings.