Can someone help me with this?

Question

Assume you see an ad for a discount on big pipe (a cylinder) that can be cut in half lengthwise and used as either a watering trough for horses or a flowerbed for your yard. Assuming water level, what is the maximum gallons of water that would fit in the trough if the pipe is 23 feet long and 27 inches in diameter.

Answer 1

First figure volume of water in cubic feet. Then multiply to get gallons. Let me look up the conversions.

Volume of a cylinder is π r² h, but you have a half cylinder. So that would be π r² h / 2.

Your length (h) is 23 feet
Your radius (r) is 13.5 inches / 12 inches/ft = 1.125 feet

So your volume is:
V = π * (1.125)² * 23 / 2

This comes out to approximately 45.7 cubic feet.

1 cu. ft in gallons (according to Google) is 7.48 gallons.

Multiply the two and you get about 342 gallons.

Answer 2

The volume of a cylinder is equal to the area of the cross section multiplied by the length.

It's easier to calculate in metric, so we convert from inches to centimetres:
Radius = 27 in / 2 = 13.5in * 2.54 cm/in = 34.3 cm
Length = 23 ft * 12 in/ft * 2.54 cm/in = 701 cm

Cross sectional area = π*radius*radius = 3694 cm^2

Volume of entire pipe = 701cm * 3694 cm^2 = 2.59*10^6 cm^3

Volume of half pipe = 1.295 * 10^6 cm^3

Since there are 1000 cubic centimetres in a litre, the volume of the half pipe is 1295 litres.

Now convert back to gallons. According to Google 1295 litres is 295 imperial gallons.

Answer 3

I think we need a little more info here before we can fully solve. Specifically we need some information along the lines of how much space 1 gallon of water takes up, or how much water 1 unit (such as 1 ft^3) can hold.

Answer 4

volume=(1/2)*3.14*27/12*27/12*23 cft
=46.7cft
46.7* 7.48051945 =gallons
=349.34 gallons

Answer 5

341.8 Gallons