Question

A cylindrical rain barrel with a diameter of 2.5 feet and a height of 3.5 feet is filled to a height of 1.5 feet. How many more gallons of water can the barrel hold? Round your answer to the nearest whole number. (1ft cubed is about 7.5 gallons)

Answer 1

The formula for solving the volume of a tank is V=pi*r²*h where "r" represent the radius and "h" for the height.

In the given problem we need to solve for the volumes,
V=3.1416*r²*h
r=diameter/2
r=2.5/2
r=1.25

h=3.5-1.5 since 1.5 is already filled with water
h=2

V=3.1416*1.25²*2
V=9.8175 ft³

Solving for how many more gallons (1 cubic feet is 7.5 gallons)
# of gallons=9.8175 *7.5/1
# of gallons=73.63 gallons