If the height of a cylinder is doubled, by what number must the radius of the base be multiplied so that the resulting cylinder has the same volumes as the original cylinder?

Let radius of cylinder = r

Let height of cylinder = h

So, volume = πr²h

Now height is doubled = 2h

So , volume = πr²×2h = 2πr²h.

To gain a volume same as original volume we have to multiply r by

New r =

Height = 2h

Volume = πr²h =