Question

A water tank is in the shape of a cylinder with a diameter of 20 feet and a height of 20 feet. The tank is 70% full. About how many gallons of water are in the tank? Round your answer to the nearest whole number.

Answer 1

32886.476 gal

Explanation:

Given:

Diameter of tank 'd'= 20 ft

∴radius 'r'= d/2=> 20/2=> 10ft

Height 'h' = 20 ft

Volume of cylinder can be determined by

V= π r² h

Substituting the values in above equation

V= π (10)² (20) =>π(100)(20)

V=2000π ft³

When the tank is 70% full.

70% of 2000π =>0.7 x 2000π

1400π ft³

As we know that, 1ft³ = 7.481 gal

1400π ft³= 1400π x 7.481 gal

1400π ft³= 32886.476 gal

Therefore, if the tank is 70% full then 32886.476 gallons of water are in the tank

Answer 2

32901 gallons

Explanation:

First, we find the volume of the cylindrical water tank when it is full.

The volume of a cylinder is given as:

V =
`\pi r^2h`

where r = radius and h = height of the cylinder

The diameter of the tank is 20 feet, hence, its radius is 10 feet.

Volume, V, is therefore:

V =
`\pi * 10^2*20 = 6283.19 ft^3`

This is the volume of the tank, when it is full.

When it is 70% full, the volume will be:

`(70)/(100) * 6283.19 = 4398.23 ft^3`

1 cubic foot (
`ft^3`) is 7.48 gallons.

Therefore, the volume of the 70% full tank in gallons will be:

4398.23 * 7.48 = 32901.05 gallons ≅ 32901 gallons

The tank contains 32901 gallons of water.