Answer:
a) benzene = 910 days
b) toluene = 1612.67 days
Explanation:
Given:
Kd = 1.8 L/kg (benzene)
Kd = 3.3 L/kg (toluene)
psolid = solids density = 2.6 kg/L
K = 2.9x10⁻⁵m/s
pores = n = 0.37
water table = 0.4 m
ground water = 15 m
u = K/n = (2.9x10⁻⁵ * (0.4/15)) / 0.37 = 2.09x10⁻⁶m/s
a) For benzene:

The time will take will be:

b) For toluene:


Scientific notation is another way to write a number. In scientific notation, the letter E is used to mean "10 to the power of." For example, 1.314E+1 means 1.314 * 101 which is 13.14 . Scientific notation is merely a format used for input and output.
Answer:
The steady-state temperature difference is 2.42 K
Explanation:
Rate of heat transfer = kA∆T/t
Rate of heat transfer = 6 W
k is the heat transfer coefficient = 152 W/m.K
A is the area of the square silicon = width^2 = (7/1000)^2 = 4.9×10^-5 m^2
t is the thickness of the silicon = 3 mm = 3/1000 = 0.003 m
6 = 152×4.9×10^-5×∆T/0.003
∆T = 6×0.003/152×4.9×10^-5 = 2.42 K
Answer:
the heat transfer from the pipe will decrease when the insulation is taken off for r₂< 
where;
r₂ = outer radius
= critical radius
Explanation:
Note that the critical radius of insulation depends on the thermal conductivity of the insulation k and the external convection heat transfer coefficient h .

The rate of heat transfer from the cylinder increases with the addition of insulation for outer radius less than critical radius (r₂<
) 0, and reaches a maximum when r₂ =
, and starts to decrease for r₂<
. Thus, insulating the pipe may actually increase the rate of heat transfer from the pipe instead of decreasing it when r₂<
.