Question

Mary wants to fill in a cylinder vase. At the flower store they told her that the vase should be filled 2/3 for the flowers to last the longest. Her cylinder vase has a radius of 3 in and a height of 8 in. Using the equation below, how much water should Mary pour into the vase?
The volume of a cylinder with height h and radius r is given by the formula:

V=πr^2h

Answer 1

Since the radius is constant, wouldn't the volume simply depend on the height of the water?
So Mary must fill it to a height of (2/3)(8) inches or 16/3 inches.

If you want the actual volume she had to pour in .....
Volume = (9π)(16/3) cubic inches
= 48π inches^3 or appr 150.8 cubic inches.

or:
volume of whole cylinder = π(9)(8) = 72π cubic inches
you want 2/3 of that which is (2/3)(72π) = 48π cubic inches
what height is that?
9π(h) = 48π
h = 48π/9π = 16/3 , just as above

Answer 2

im still kinda confused

Answer 3

i dont think this really helped cus im confused...