Question

given the height, h, and the volume V of a certain cylinder, alex uses the formula r=√v/πh to compute its radius, r, to be 10 meters. a second cylinder has the same volume as the first cylinder, but is 25 times taller. what is the radius of the second cylinder?

a). 2/5 meter
b). 2 meters
c). 50 meters
d). 250 meters

Answer 1

$r \: = \: \sqrt{ \frac{v}{\pi .h} } \: = \: 10 \: m$
${r}^{.} \: = \: \sqrt{ \frac{v}{25h\pi} } \: = \: \frac{1}{5} \sqrt{ \frac{v}{\pi.h} } \: = \: \frac{10}{5} \: m \: = \: 2 \: m$