The soil temperature in the upper layers of the earth varies with the variations in the atmospheric conditions. Before a cold front moves in, the earth at a location is initially at a uniform temperature of 10°C. Then, the area is subjected to a temperature of â8°C and high winds that result in a convection heat transfer coefficient of 40 W/m2âK on the earthâs surface for a period of 10 h. Taking the properties of the soil at that location to be k = 0.9 W/mâK and α = 1.6Ã10â5 m2/s, determine the soil temperature at distances 0, 10, 20, and 50 cm from the earthâs surface at the end of this 10-h period.

The temperature of air decreases as it is compressed by an adiabatic compressor. a)- true b)- false

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

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.