Question

HELLO FRIENDS I HAVE A QUESTION

Answer 1

we know that, volume of cylinder=

$\pi \: {r}^{2} h$

if height is doubled then volume will be

$2\pi \: {r}^{2} h$

it means volume also get doubled

and surface area of cylinder is $2\pi\: {r}^{2}+2\pi\:r h$
and when height get doubled then = $2\pi\: {r}^{2} +4\pi\:r h$

Answer 2

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As we all know that

• Volume of cylinder = πr^2h

• Surface area of cylinder = 2πr^2h

Let's go through the given question !

=> How many times do the volume and surface area of a cylinder increase if it's radius remains same and the height is doubled ?

According to the given question !

In First Case :-

Old volume = πr^2h

New Volume = πr^2 ( 2 h )

New Volume = 2 ( πr^2h)

New Volume = 2 × old volume ✓

In Second Case:-

Old surface area = 2πr^2h

New surface area = 2πr^2h×2

New Surface area =2× old surface area !.

By using the formula of T. S. A that is = 2πr ( h + r ) sq units .

We can't find the exact answer by using T.S.A

As our questions was about how much "times "the surface area will increase .

According to the formula of T.S.A it will neither increase by 2 , 3 , 4 or any times or we can say that we can't find the exact answer by using T.S.A.