Answer:
(b)False
Explanation:
Given:
Prandtl number(Pr) =1000.
We know that 
Where 
is the molecular diffusivity of momentum
is the molecular diffusivity of heat.
Prandtl number(Pr) can also be defined as
Where 
is the hydrodynamic boundary layer thickness and 
is the thermal boundary layer thickness.
So if Pr>1 then hydrodynamic boundary layer thickness will be greater than thermal boundary layer thickness.
In given question Pr>1 so hydrodynamic boundary layer thickness will be greater than thermal boundary layer thickness.
So hydrodynamic layer will be thicker than the thermal boundary layer.
The design speed was used for the freeway exit ramp is 11 mph.
<h3>Design speed used in the exit ramp</h3>
The design speed used in the exit ramp is calculated as follows;
f = v²/15R - 0.01e
where;
v = ωr
v = (θ/t) r
θ = 90⁰ = 1.57 rad
v = (1.57 x 19.4)/2.5 s
v = 12.18 ft/s = 8.3 mph
<h3>Design speed</h3>
f = v²/15R - 0.01e
let the maximum superelevation, e = 1%
f = (8.3)²/(15 x 19.4) - 0.01
f = 0.22
0.22 is less than value of f which is 0.4
<h3>next iteration, try 10 mph</h3>
f = (10)²/(15 x 19.4) - 0.01
f = 0.33
0.33 is less than 0.4
<h3>next iteration, try 11 mph</h3>
f = (11)²/(15 x 19.4) - 0.01
f = 0.4
Thus, the design speed was used for the freeway exit ramp is 11 mph.
Learn more about design speed here: brainly.com/question/22279858
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Answer:
a)Patm=135.95Kpa
b)Pabs=175.91Kpa
Explanation:
the absolute pressure is the sum of the water pressure plus the atmospheric pressure, which means that for point a we have the following equation
Pabs=Pw+Patm(1)
Where
Pabs=absolute pressure
Pw=Water pressure
Patm=
atmospheric pressure
Water pressure is calculated with the following equation
Pw=γ.h(2)
where
γ=especific weight of water=9.81KN/M^3
H=depht
A)
Solving using ecuations 1 y 2
Patm=Pabs-Pw
Patm=185-9.81*5=135.95Kpa
B)
Solving using ecuations 1 y 2, and atmospheric pressure
Pabs=0.8x5x9.81+135.95=175.91Kpa
Answer:
Heat losses by convection, Qconv = 90W
Heat losses by radiation, Qrad = 5.814W
Explanation:
Heat transfer is defined as the transfer of heat from the heat surface to the object that needs to be heated. There are three types which are:
1. Radiation
2. Conduction
3. Convection
Convection is defined as the transfer of heat through the actual movement of the molecules.
Qconv = hA(Temp.final - Temp.surr)
Where h = 6.4KW/m2K
A, area of a square = L2
= (0.25)2
= 0.0625m2
Temp.final = 250°C
Temp.surr = 25°C
Q = 64 * 0.0625 * (250 - 25)
= 90W
Radiation is a heat transfer method that does not rely upon the contact between the initial heat source and the object to be heated, it can be called thermal radiation.
Qrad = E*S*(Temp.final4 - Temp.surr4)
Where E = emissivity of the surface
S = boltzmann constant
= 5.6703 x 10-8 W/m2K4
Qrad = 5.6703 x 10-8 * 0.42 * 0.0625 * ((250)4 - (25)4)
= 5.814 W
Answer:
A blizzard
Explanation:
You could be trapped in your car for days
