Answer:
Step-by-step explanation:
Answer:
793 liters of washing fluid is needed
Step-by-step explanation:
step 1
Find the slant height of the triangular faces of pyramid
we know that
The lateral area of a square pyramid is equal to the area of its four triangular faces
so
![LA=4[\frac{1}{2}bl]](https://tex.z-dn.net/?f=LA%3D4%5B%5Cfrac%7B1%7D%7B2%7Dbl%5D)
where
b is the base of triangle (is the same that the length of the square base)
l is the slant height
To find out the slant height we need to apply the Pythagorean Theorem
so
![l^2=(b/2)^2+h^2](https://tex.z-dn.net/?f=l%5E2%3D%28b%2F2%29%5E2%2Bh%5E2)
we have
![b=35.42\ m](https://tex.z-dn.net/?f=b%3D35.42%5C%20m)
![h=21.64\ m](https://tex.z-dn.net/?f=h%3D21.64%5C%20m)
substitute
![l^2=(35.42/2)^2+21.64^2](https://tex.z-dn.net/?f=l%5E2%3D%2835.42%2F2%29%5E2%2B21.64%5E2)
![l^2=781.9337](https://tex.z-dn.net/?f=l%5E2%3D781.9337)
![l=27.96\ m](https://tex.z-dn.net/?f=l%3D27.96%5C%20m)
step 2
Find the lateral area of the pyramid
![LA=4[\frac{1}{2}bl]](https://tex.z-dn.net/?f=LA%3D4%5B%5Cfrac%7B1%7D%7B2%7Dbl%5D)
we have
![l=27.96\ m](https://tex.z-dn.net/?f=l%3D27.96%5C%20m)
![b=35.42\ m](https://tex.z-dn.net/?f=b%3D35.42%5C%20m)
substitute
![LA=4[\frac{1}{2}(35.42)(27.96)]](https://tex.z-dn.net/?f=LA%3D4%5B%5Cfrac%7B1%7D%7B2%7D%2835.42%29%2827.96%29%5D)
![LA=1,980.6864\ m^2](https://tex.z-dn.net/?f=LA%3D1%2C980.6864%5C%20m%5E2)
step 3
Find out how much window washing fluid is needed
we know that
2 L of washing fluid cover 5 square meters
so
using proportion
![\frac{2}{5}\ \frac{L}{m^2}=\frac{x}{1,980.6864}\ \frac{L}{m^2}\\\\x=1,980.6864(2)/5\\\\x= 792.27\ L](https://tex.z-dn.net/?f=%5Cfrac%7B2%7D%7B5%7D%5C%20%5Cfrac%7BL%7D%7Bm%5E2%7D%3D%5Cfrac%7Bx%7D%7B1%2C980.6864%7D%5C%20%5Cfrac%7BL%7D%7Bm%5E2%7D%5C%5C%5C%5Cx%3D1%2C980.6864%282%29%2F5%5C%5C%5C%5Cx%3D%20792.27%5C%20L)
Round up
793 liters of washing fluid is needed
130 if you round that to the nearest whole number then you’ll get 139
1 mile = 5,280 feet:
9 miles x 5280 feet per mile = 47,520 total feet per hour
1 hour = 3600 seconds.
Divide total feet by seconds per hour:
47,520 feet / 3600 seconds per hour = 13.2 feet per second.
Multiply feet per second by number of seconds for distance traveled:
13.2 feet per second x 15 seconds = 198 total feet.