Question

if a cylinder with height 9 inches and radius r is filled with water, it can fill a certain pitcher. how many of these pitchers can a cylinder with height 9 inches and radius 2r fill? explain how you know.

Answer 1

Answer:

4 pitchers

Step-by-step explanation:

we know that

The volume of a cylinder is equal to

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

step 1

Find the volume of the cylinder  with height 9 inches and radius r

substitute the given values

$V_1=\pi r^{2}(9)$

$V_1=9\pi r^{2}\ in^3$

step 2

Find the volume of the cylinder  with height 9 inches and radius 2r

substitute the given values

$V_2=\pi (2r)^{2}(9)$

$V_2=36\pi r^{2}\ in^3$

step 3

we know that

The volume of the cylinder 1 can fill a certain pitcher,

so

The volume of the pitcher is the same that the volume of cylinder 1

therefore

the number of pitchers that can be filled by the second cylinder is equal to divide the volume of the second cylinder by the volume of the first cylinder

$\frac{36\pi r^{2}}{9\pi r^{2}}=4\ pitchers$