Answer:
(a) Flow rate of vehicles = No of vehicles per mile * Speed
=No of cars per mile * Speed +No of trucks per mile * Speed
= 0.75*50*60 + 0.25*50*40
=2750 vehicles / hour
(b) Let Density of vehicles on grade = x
Density on flat * Speed =Density on grade * Speed
So,( 0.75*50) * 60 + (0.25*50) * 40 = (0.75* x) * 55 + (0.25* x) * 25
So, x= 57.89
So, Density is around 58 Vehicles per Mile.
(c) Percentage of truck by aerial photo = 25%
(d)Percentage of truck bystationary observer on the grade= 25*30/60 * 25/55 =22.73 %
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
Carbon is not used as semiconductor it has 4 valence electrons in it valence shell but the energy gap is very small it will conduct electricity even at room temperature ,the size of carbon is very small .
But where are the options?
Answer:
The metal Harvey should use for reflective coatings in telescope mirror is;
C. Aluminum
Explanation:
In a telescope, the mirror of the telescope is usually made of a temperature-resistant and strong glass, while the reflective coating of the mirrors is made usually from aluminum. A protective coating often composed of silicon dioxide is placed n the top of the reflective coating
Aluminum is used in a telescope, rather than the silver, which is the most reflective material, because silver requires special conditions to be able to work, and silver tarnishes when exposed to air containing sulfur, and silver is susceptible to corrode.
