Answer:
-Differential equation: d²T/dx² = 0
-The boundary conditions are;
1) Heat flux at bottom;
-KAdT(0)/dx = ηq_e
2) Heat flux at top surface;
-KdT(L)/dx = h(T(L) - T(water))
Explanation:
To solve this question, let's work with the following assumptions that we are given;
- Heat transfer is steady and one dimensional
- Thermal conductivity is constant.
- No heat generation exists in the medium
- The top surface which is at x = L will be subjected to convection while the bottom surface which is at x = 0 will be subjected to uniform heat flux.
Will all those assumptions given, the differential equation can be expressed as; d²T/dx² = 0
Now the boundary conditions are;
1) Heat flux at bottom;
q(at x = 0) is;
-KAdT(0)/dx = ηq_e
2) Heat flux at top surface;
q(at x = L):
-KdT(L)/dx = h(T(L) - T(water))
Answer: 33.35 minutes
Explanation:
A(t) = A(o) *(.5)^[t/(t1/2)]....equ1
Where
A(t) = geiger count after time t = 100
A(o) = initial geiger count = 400
(t1/2) = the half life of decay
t = time between geiger count = 66.7 minutes
Sub into equ 1
100=400(.5)^[66.7/(t1/2)
Equ becomes
.25= (.5)^[66.7/(t1/2)]
Take log of both sides
Log 0.25 = [66.7/(t1/2)] * log 0.5
66.7/(t1/2) = 2
(t1/2) = (66.7/2 ) = 33.35 minutes
In general, bury metal conduits at least 6 inches below the soil surface. You may also run them at a depth of 4 inches under a 4-inch concrete slab. Under your driveway, the conduits must be below a depth of 18 inches, and under a public road or alleyway, they must be buried below 24 inches.
Answer:
(a) pulse-amplitude modulation (PAM)
Explanation:
It should be no surprise that pulse amplitude is modulated in <em>pulse-amplitude modulation (PAM)</em>.