Answer:
The velocity at R/2 (midway between the wall surface and the centerline) is given by (3/4)(Vmax) provided that Vmax is the maximum velocity in the tube.
Explanation:
Starting from the shell momentum balance equation, it can be proved that the velocity profile for fully developedblaminar low in a circular pipe of internal radius R and a radial axis starting from the centre of the pipe at r=0 to r=R is given as
v = (ΔPR²/4μL) [1 - (r²/R²)]
where v = fluid velocity at any point in the radial direction
ΔP = Pressure drop across the pipe
μ = fluid viscosity
L = pipe length
But the maximum velocity of the fluid occurs at the middle of the pipe when r=0
Hence, maximum veloxity is
v(max) = (ΔPR²/4μL)
So, velocity at any point in the radial direction is
v = v(max) [1 - (r²/R²)]
At the point r = (R/2)
r² = (R²/4)
(r²/R²) = r² ÷ R² = (R²/4) ÷ (R²) = (1/4)
So,
1 - (r²/R²) = 1 - (1/4) = (3/4)
Hence, v at r = (R/2) is given as
v = v(max) × (3/4)
Hope this Helps!!!
The technician should start by checking the temperature rise across the indoor coil.
<h3>Who is a technician?</h3>
This is a person who has skill in a particular area of job. A technician is responsible for repairs and also ensure different equipment and systems are working perfectly.
Hence, the technician should start by checking the temperature rise across the indoor coil.
Learn more about technician here : brainly.com/question/13315405
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EPA Regulations provides a certified course for the technicians involved in the Air-conditioning system.
Answer: Option (b)
<u>Explanation:</u>
The EPA regulation has implemented an act called the "Clean Air Act" under the "section of 609".
This act provides some basic requirements for EPA Regulation such as follows;
- Refrigerant: This unit must be approved by EPA Regulations before being implemented into the atmosphere.
- Servicing: This system provides a certified course for technicians in service and also approve them with proper refrigerant equipment.
- Reuse Refrigerants: The use of recycled refrigerants must be properly monitored before it comes in to serve.
Solution :
Given :
External diameter of the hemispherical shell, D = 500 mm
Thickness, t = 20 mm
Internal diameter, d = D - 2t
= 500 - 2(20)
= 460 mm
So, internal radius, r = 230 mm
= 0.23 m
Density of molten metal, ρ = 
= 
The height of pouring cavity above parting surface is h = 300 mm
= 0.3 m
So, the metallostatic thrust on the upper mold at the end of casting is :
Area, A 
= 7043.42 N
Answer:
d. 2.3 ohms (5.3 amperes)
Explanation:
The calculator's 1/x key makes it convenient to calculate parallel resistance.
Req = 1/(1/4 +1/8 +1/16) = 1/(7/16) = 16/7 ≈ 2.3 ohms
This corresponds to answer choice D.
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<em>Additional comment</em>
This problem statement does not tell the applied voltage. The answer choices suggest that it is 12 V. If so, the current is 12/(16/7) = 21/4 = 5.25 amperes.
