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


Answer:
Explanation:
Total distance covered = 25 + 15 = 40 m
Total time = 15 + 8 = 23 s
Average speed = total distance covered / total time
= 40 / 23
= 1.74 m / s
Total displacement = 25 - 15 = 10 m
Total time = 15 + 8 = 23 s
Average velocity = total displacement / total time
= 10 / 23
= .434 m / s to the right .
Answer:
0.68 s
Explanation:
We are given that
Initial velocity of box=
Final velocity of box=v=11.5 m/s
Distance=d=8.5 m
We have to find the time taken by box to slow by this amount.
We know that

Substitute the values




We know that
Acceleration=
Substitute the values



Hence, the time taken by box to slow by this amount=0.68 s
Answer:
0.853 m/s
Explanation:
Total energy stored in the spring = Total kinetic energy of the masses.
1/2ke² = 1/2m'v².................... Equation 1
Where k = spring constant of the spring, e = extension, m' = total mass, v = speed of the masses.
make v the subject of the equation,
v = e[√(k/m')].................... Equation 2
Given: e = 39 cm = 0.39 m, m' = 0.4+0.4 = 0.8 kg, k = 1.75 N/cm = 175 N/m.
Substitute into equation 2
v = 0.39[√(1.75/0.8)
v = 0.39[2.1875]
v = 0.853 m/s
Hence the speed of each mass = 0.853 m/s
Answer:
<em>The average speed of the train is 45 km/h</em>
Explanation:
<u>Speed</u>
It's defined as the distance (d) per unit of time (t) traveled by an object. The formula is:

Let's call x the total distance covered by the train. It covered d1=1/3x with a speed of v1=25 km/h. The time taken is calculated solving for t:



Now the rest of the distance:
d2 = x - 1/3x = 2/3x
Was covered at v2=75 km/h. Thus the time taken is:



The total time is:



Simplifying:

The average speed is the total distance divided by the total time:

Simplifying:

The average speed of the train is 45 km/h