Answer:
50 miles per hour
Step-by-step explanation:
First one is a distance
Second one is time
Last one doesn't make sense
 
        
                    
             
        
        
        
Answer:
Radius =6.518 feet
Height = 26.074 feet
Step-by-step explanation:
The Volume of the Solid formed  = Volume of the two Hemisphere + Volume of the Cylinder
Volume of a Hemisphere  
Volume of a Cylinder 
Therefore: 
The Volume of the Solid formed 

Area of the Hemisphere =
Curved Surface Area of the Cylinder =
Total Surface Area=
 
Cost of the Hemispherical Ends  = 2 X  Cost of the surface area of the sides.
Therefore total Cost, C
 
Recall: 
Therefore:
 
The minimum cost occurs at the point where the derivative equals zero.


![-27840+32\pi r^3=0\\27840=32\pi r^3\\r^3=27840 \div 32\pi=276.9296\\r=\sqrt[3]{276.9296} =6.518](https://tex.z-dn.net/?f=-27840%2B32%5Cpi%20r%5E3%3D0%5C%5C27840%3D32%5Cpi%20r%5E3%5C%5Cr%5E3%3D27840%20%5Cdiv%2032%5Cpi%3D276.9296%5C%5Cr%3D%5Csqrt%5B3%5D%7B276.9296%7D%20%3D6.518)
Recall:

Therefore, the dimensions that will minimize the cost are:
Radius =6.518 feet
Height = 26.074 feet