Select the correct answer.

If a fire is burning a building and it takes 2 hours to put it out using 2000 gal./min., what minimum diameter cylindrical tank

strojnjashka [21]

Answer:

The minimum diameter of the cylindrical tank needed to store the quantity needed to put out the fire is approximately 58.415 feet.

Step-by-step explanation:

A gallon equals 0.134 cubic feet. First, we determine the amount of water ( $Q$ ), measured in cubic feet, needed to put out the fire under the assumption that water is consumed at constant rate:

$Q = \dot Q \cdot \Delta t$ (1)

Where:

$\dot Q$ - Volume rate, measured in feet per minute.

$\Delta t$ - Time, measured in minutes.

If we know that $\dot Q = 2000\,\frac{gal}{min}$ and $\Delta t = 120\,min$ , then the amount of water is:

$Q = \left(2000\,\frac{gal}{min} \right)\cdot (120\,min) \cdot \left(0.134\,\frac{ft^{3}}{gal} \right)$

$Q = 32160\,ft^{3}$

And the diameter of the cylindrical tank based on the capacity found above is determined by volume formula for a cylinder:

$Q = \frac{\pi}{4}\cdot D^{2}\cdot h$ (2)

Where:

$D$ - Diameter, measured in feet.

$h$ - Height, measured in feet.

If we know that $Q = 32160\,ft^{3}$ and $h = 12\,ft$ , then the minimum diameter is:

$D^{2} = \frac{4\cdot Q}{\pi\cdot h}$

$D = 2\cdot \sqrt{\frac{Q}{\pi\cdot h} }$

$D = 2\cdot \sqrt{\frac{32160\,ft^{3}}{\pi\cdot (12\,ft)} }$

$D \approx 58.415\,ft$

The minimum diameter of the cylindrical tank needed to store the quantity needed to put out the fire is approximately 58.415 feet.

8 0

3 years ago

1.73639 rounded to the nearest thousanth

Maurinko [17]

^ is in the thousadths place so look for the number before it, which is 3. 3 is less than 5 so 6 stays as is so it becomes 1.736

8 0

3 years ago

The difference between a number,x, and 4 is 9. find the number

Elena-2011 [213]

let's set up an equation:

x-4=9

solve normally:

x=13

6 0

3 years ago

The area of a rectangle is 66 ft2, and the length of the rectangle is 1 ft more than twice the width. Find the dimensions of the

umka21 [38]

This is probably way overcomplicated but i cant remember how to do it
w = n
l = 2n+1
w*l = 66
n(2n+1) = 66
2n^2 + n =66
2n^2 + n - 66 = 0
using quadratic equation

n = 11/2

width = 11/2 = 5.5
length = 11 + 1 = 12

3 0

3 years ago

Roberta makes $9 an hour plus a 10.5% commission selling jewelry an hour shift in which she sells $880 worth of jewelry. How muc

timama [110]

Answer:

Roberta earns $164.4 on an 8 hr shift.

Step-by-step explanation:

In one hour Roberta makes $9

So if she works for 8 hours she will be making

=> ( 9 X 8)$

=>72$

Also she earns a commission of 10.5% on selling a jewellery worth $880

So 10.5% of 880 is

=> $\frac{10.5}{100}\times 880$

=> $0.105\times 880$

=> 92.4

Hence Roberta will be earning a total amount of

(72+ 92.4)

=>$164.4

3 0

3 years ago