If it is stationary, its not moving. there is no movement
        
             
        
        
        
Answer:
- The velocity component in the flow direction is much larger than that in the normal direction ( A )
-  The temperature and velocity gradients normal to the flow are much greater than those along the flow direction ( b )
Explanation:
For a steady two-dimensional flow the boundary layer approximations are The velocity component in the flow direction is much larger than that in the normal direction and The temperature and velocity gradients normal to the flow are much greater than those along the flow direction 
assuming Vx ⇒ V∞ ⇒ U and Vy ⇒ u from continuity equation we know that
Vy << Vx
 
        
             
        
        
        
There are many ways to solve this but I prefer to use the energy method. Calculate the potential energy using the point then from Potential Energy convert to Kinetic Energy at each points.
PE = KE
From the given points (h1 = 45, h2 = 16, h<span>3  </span>= 26)
Let’s use the formula: 
v2= sqrt[2*Gravity*h1]  where the gravity is equal to 9.81m/s2
v3= sqrt[2*Gravity*(h1 - h3 )] where the gravity is equal to 9.81m/s2
v4= sqrt[2*Gravity*(h1 – h2)] where the gravity is equal to 9.81m/s2
Solve for v2
v2= sqrt[2*Gravity*h1]      
    = √2*9.81m/s2*45m
v2= 29.71m/s
v3= sqrt[2*Gravity*(h1 - h3 )   
    =√2*9.81m/s2*(45-26)
    =√2*9.81m/s2*19 
v3=19.31m/s
v4= sqrt[2*Gravity*(h1 – h2)]        
    =√2*9.81m/s2*(45-16)
    =√2*9.81m/s2*(29)
v4=23.85m/s
 
        
             
        
        
        
Answer:
F = (500 ± 4) 10² lb
Explanation:
This is an exercise in the uncertainty or error of a measurement.
If a single measurement is made, the way to give the result is the measurement value plus the appreciation of the instrument that corresponds to the absolute error, in the form
            F = x ± Δx
            
For this, a suitable uniform is the use of scientific notation, where each magnitude is written with an integer and some decimals multiplied by an exponential.
            X = 50067 lb = 5.0067 10⁴ lb
the uncertainty is
            Δx = 400 lb = 4.00 10² lb
so the result for the report must be written
           F = (500 ± 4) 10² lb
where the significant figures are adjusted to the measurement error.
In the case of making a series of measurements, the value obtained is the average of the measurements and the error must be given by the standard deviation