Question

The ratio of the radii of two cylinder of same height is 1 ratio 3. If the volume of first cylinder is 50 cm2 then find the volume of second cylinder

Answer 1

Answer:

Let r1 and r2 be radii of two cyclinder and V1, V2  be their volume .  

Let h be height of the two cyclinders, then  

V1 = πr2h and V2  =  πr22h  

∴  V1 /  V2 =  πr12h /  πr22h  = r12 / r22 = 16 / 25 .  

There's an alternate method too:

ratio of radii = 4:5

ratio of CSA= 4:5 ( to show)

ratio of volume= 16:25( to show)  

let height be h  

then the CSA = 2πr h/ 2πrh

from here we get = 4:5

same in volume = πr²h / πr²h

= 4²/5²

= 16: 25