In the illustration below, the three cube-shaped tanks are identical. The spheres in any given tank
are the same size and packed wall-to-wall. If each of the tanks are filled to the top with water, which
tank would contain the most water. Prove your answer algebraically using x to represent the edge
length of the tanks.

Write an expression to represent the amount of water remaining in a 4th tank which is the same size
as the others and which contains 512 spheres. Leave your expression in terms of π.

Respuesta :

Answer:

1) Volume occupied by the spheres are equal therefore the three tanks contains the same volume of water

2) [tex]Amount \ of \, water \ remaining \ in \, the \ tank \ is \ \frac{x^3(6-\pi) }{6}[/tex]

Step-by-step explanation:

1) Here we have;

First tank A

Volume of tank = x³

The  volume of the sphere = [tex]\frac{4}{3} \pi r^3[/tex]

However, the diameter of the sphere = x therefore;

r = x/2 and the volume of the sphere is thus;

volume of the sphere = [tex]\frac{4}{3} \pi \frac{x^3}{8}[/tex]= [tex]\frac{1}{6} \pi x^3[/tex]

For tank B

Volume of tank = x³

The  volume of the spheres = [tex]8 \times \frac{4}{3} \pi r^3[/tex]

However, the diameter of the spheres 2·D = x therefore;

r = x/4 and the volume of the sphere is thus;

volume of the spheres = [tex]8 \times \frac{4}{3} \pi (\frac{x}{4})^3= \frac{x^3 \times \pi }{6}[/tex]

For tank C

Volume of tank = x³

The  volume of the spheres = [tex]64 \times \frac{4}{3} \pi r^3[/tex]

However, the diameter of the spheres 4·D = x therefore;

r = x/8 and the volume of the sphere is thus;

volume of the spheres = [tex]64 \times \frac{4}{3} \pi (\frac{x}{8})^3= \frac{x^3 \times \pi }{6}[/tex]

Volume occupied by the spheres are equal therefore the three tanks contains the same volume of water

2) For the 4th tank, we have;

number of spheres on side of the tank, n is given thus;

n³ = 512

∴ n = ∛512 = 8

Hence we have;

Volume of tank = x³

The  volume of the spheres = [tex]512 \times \frac{4}{3} \pi r^3[/tex]

However, the diameter of the spheres 8·D = x therefore;

r = x/16 and the volume of the sphere is thus;

volume of the spheres = [tex]512\times \frac{4}{3} \pi (\frac{x}{16})^3= \frac{x^3 \times \pi }{6}[/tex]

Amount of water remaining in the tank is given by the following expression;

Amount of water remaining in the tank = Volume of tank - volume of spheres

Amount of water remaining in the tank = [tex]x^3 - \frac{x^3 \times \pi }{6} = \frac{x^3(6-\pi) }{6}[/tex]

[tex]Amount \ of \ water \, remaining \, in \, the \ tank = \frac{x^3(6-\pi) }{6}[/tex].