Question

A water storage tank has the shape of a cylinder with diameter 14 ft. It is mounted so that the circular cross-sections are vertical. If the depth of the water is 12 ft, what percentage of the total capacity is being used? (Round your answer to one decimal place.) %

Answer 1

Answer:

percentage of the total capacity is 75.6%

Step-by-step explanation:

Hello! To solve this problem we follow the following steps

1. draw the complete scheme of the problem (see attached image)

2. To solve this problem we must find the area of ​​the circular sector using the following equation.(c in the second attached image)

$A=\frac{R^2}{2} (\alpha -sin\alpha )$

$\alpha =2arccos(\frac{d}{R})$

3. observing the attached images we replace the values ​​in the equations and find the area of ​​the circular sector, remember that you must transform the angle to radians

$\alpha =2arccos(\frac{5}{7})=88.83$

$A=\frac{R^2}{2} (\alpha -sin\alpha )\\A=\frac{7^2}{2} (88.83-sen88.83)*\frac{\pi rad}{180} =37.57ft^2$

4.we calculate the area of ​​the total circle (At), then subtract the area of ​​the circular sector (Ac) to find the area occupied by water (Aw)

$At=\frac{\pi }{4} (14ft)^2=153.93ft^2$

Aw=At-Ac=153.93-37.57=116.36ft^2

5.Finally, we calculate the percentage that represents the water in the tank by dividing the area of ​​the water over the total area of ​​the tank

$\frac{116.36}{153.93} *100=75.6$

percentage of the total capacity is 75.6%