An open-top cylindrical tank with a volume of 20m3 is to be made from a sheet of steel. If the cylindrical height is 5m, what is the surface area of steel?

Question

what is the surface area of steel required to complete the tank? Please explain the steps.

Answer 1

You have a cylinder, so you want the formula of the surface area of this solid.  The height, h, is 5cm.

 

SA = πr² + 2πrh

SA = πr² + 10πr

 

 

You also need to know the volume of this solid.

 

V = πr²h

 

 

The volume is already given to you.

 

πr²h = 20

5πr² = 20

 

Then, from this volume equation, your radius, r, is

 

r² = 4 / π

 

r = 2 / √π

 

 

Plug in this value of r into the SA formula to get the actual surface area.