Answer:
If Reynolds number increases the extent of the region around the object that is affected by viscosity decreases.
Explanation:
Reynolds number is an important dimensionless parameter in fluid mechanics.
It is calculated as;
where;
ρ is density
v is velocity
d is diameter
μ is viscosity
All these parameters are important in calculating Reynolds number and understanding of fluid flow over an object.
In aerodynamics, the higher the Reynolds number, the lesser the viscosity plays a role in the flow around the airfoil. As Reynolds number increases, the boundary layer gets thinner, which results in a lower drag. Or simply put, if Reynolds number increases the extent of the region around the object that is affected by viscosity decreases.
Answer:
Explanation:
The step by step analysis is as shown in the attached files.
Answer: True
Explanation: Ceramics have the property that when the band gap present between the atoms are larger than the light energy then the tend to become opaque because the light scattering is caused . They also show the property of being translucent when there are chances of the light to get a path through the surface of ceramic so they get the light at some parts e.g.porcelain .Therefore the statement given is true that ceramics can be optically opaque or semi-transparent(translucent).
Answer:
BOD concentration at the outflow = 17.83 mg/L
Explanation:
given data
flow rate of Q = 4,000 m³/day
BOD1 concentration of Cin = 25 mg/L
volume of the pond = 20,000 m³
first-order rate constant equal = 0.25/day
to find out
What is the BOD concentration at the outflow of the pond
solution
first we find the detention time that is
detention time t = 
detention time t = 
detention time = 5 days
so
BOD concentration at the outflow of pond is express as
BOD concentration at the outflow = 
here k is first-order rate constant and t is detention time and Cin is BOD1 concentration
so
BOD concentration at the outflow = 
BOD concentration at the outflow = 17.83 mg/L
