A) In the case of the Boundary Thickness Layer we use the given formula,

We know as well that,
Re = Número de Reynolds = 
Where,
U = velocity
= kinematic viscosity
For water, kinematic viscosity, 
So, 



B) For flat plate boundary layer. Given the Critical Reynolds Number.= 5*10^5 we know that is equal to Re above.
Thus, 
C. Wall shear stress,

For water, dynamic viscosity,
= 2.344*10^-5 lbf-s/ft^2


<span>Inertia is a property of matter
i hope this help</span>
To solve this exercise it is necessary to take into account the concepts related to thermal expansion.
The thermal expansion is given by the function,

Where,
Change in Length
Change in Temperature
Coeficiente de dilatación lineal
Initial Length
By quickly deducing the formula, we can realize that the greater the change in temperature, the greater the change in the length of the radius.
The change in length is proportional to the change in temperature. Considering that the other two terms are constant we have that the correct one would be: <em>The hole in the center of the washer will expand.</em>