Question

The volume and whole surface area of a cylindrical solid of radius 'r' units are v and s respectively if height of cylinder is i unit .then v/s =

Answer 1

Answer:A. 1/2(1-1/r+1)

Step-by-step explanation:since...

V/S = πrsquare h/2πr(h+r)

=rh/2(h+r)

=r/2r+2 ( since : h=1)

while, 1/2(1-1/r+1)

=1/2- 1/2r+2

= 2r+2-2/4r+4

=2r/4r+4

= r/2r+2

hence both of then ar equal.so I hope this helps u..

Answer 2

Answer:

The ratio of V/S is ½ ( 1 - 1/(1+r) )..

Step-by-step explanation:

Given that :

• radius of cylinder = r
• height of cylinder = h =1
• Volume of cylinder = V
• Total Surface Area of cylinder = S

To find :

• ratio of V/S

Solution :

• The volume of cylinder whose radius is r and height is h, is given by

$V= \pi{r}^{2} h$

• Total Surface Area of cylinder is

$S =2 \pi \: r( h+ r)$

• The ratio of V/S is

$\frac{V}{S} = \frac{\pi {r}^{2}h }{2\pi \: r(h + r)} \\ = \frac{rh}{2(h + r)}$

• Putting h = 1 in above equation, we get

$V/S = \frac{r}{2(1 + r)} \\ = \frac{(1 + r)- 1}{2(1 + r)} \\ = \frac{1}{2} (1 - \frac{1}{1 + r} )$

• Hence, ratio of V/S is ½ ( 1 - 1/(1+r) ) .