Answer:
True
Explanation:
The tensile forces are small in most arches and usually negligible.
Answer:
the pressure at a closed valve attached to the tank 10 ft above its bottom is 37.88 psi
Explanation:
Given that;
depth 1 = 71 ft
depth 2 = 10 ft
pressure p = 17 psi = 2448 lb/ft²
depth h = 71 ft - 10 ft = 61 ft
we know that;
p = P_air + yh
where y is the specific weight of ethyl alcohol ( 49.3 lb/ft³ )
so we substitute;
p = 2448 + ( 49.3 × 61 )
= 2448 + 3007.3
= 5455.3 lb/ft³
= 37.88 psi
Therefore, the pressure at a closed valve attached to the tank 10 ft above its bottom is 37.88 psi
Solution:
Given that :
Volume flow is, ![$Q_1 = 1000 \ mm^3/s$](https://tex.z-dn.net/?f=%24Q_1%20%3D%201000%20%5C%20mm%5E3%2Fs%24)
So, ![$Q_2= \frac{1000}{100}=10 \ mm^3/s$](https://tex.z-dn.net/?f=%24Q_2%3D%20%5Cfrac%7B1000%7D%7B100%7D%3D10%20%5C%20mm%5E3%2Fs%24)
Therefore, the equation of a single straight vessel is given by
......................(i)
So there are 100 similar parallel pipes of the same cross section. Therefore, the equation for the area is
![$\frac{\pi d_1^2}{4}=1000 \times\frac{\pi d_2^2}{4} $](https://tex.z-dn.net/?f=%24%5Cfrac%7B%5Cpi%20d_1%5E2%7D%7B4%7D%3D1000%20%5Ctimes%5Cfrac%7B%5Cpi%20d_2%5E2%7D%7B4%7D%20%24)
or ![$d_1=10 \ d_2$](https://tex.z-dn.net/?f=%24d_1%3D10%20%5C%20d_2%24)
Now for parallel pipes
...........(ii)
Solving the equations (i) and (ii),
![$\frac{H_{f_1}}{H_{f_2}}=\frac{\frac{8flQ_1^2}{\pi^2 gd_1^5}}{\frac{8flQ_2^2}{\pi^2 gd_2^5}}$](https://tex.z-dn.net/?f=%24%5Cfrac%7BH_%7Bf_1%7D%7D%7BH_%7Bf_2%7D%7D%3D%5Cfrac%7B%5Cfrac%7B8flQ_1%5E2%7D%7B%5Cpi%5E2%20gd_1%5E5%7D%7D%7B%5Cfrac%7B8flQ_2%5E2%7D%7B%5Cpi%5E2%20gd_2%5E5%7D%7D%24)
![$=\frac{Q_1^2}{Q_2^2}\times \frac{d_2^5}{d_1^5}$](https://tex.z-dn.net/?f=%24%3D%5Cfrac%7BQ_1%5E2%7D%7BQ_2%5E2%7D%5Ctimes%20%5Cfrac%7Bd_2%5E5%7D%7Bd_1%5E5%7D%24)
![$=\frac{(1000)^2}{(10)^2}\times \frac{d_2^5}{(10d_2)^5}$](https://tex.z-dn.net/?f=%24%3D%5Cfrac%7B%281000%29%5E2%7D%7B%2810%29%5E2%7D%5Ctimes%20%5Cfrac%7Bd_2%5E5%7D%7B%2810d_2%29%5E5%7D%24)
![$=\frac{10^6}{10^7}$](https://tex.z-dn.net/?f=%24%3D%5Cfrac%7B10%5E6%7D%7B10%5E7%7D%24)
Therefore,
![$\frac{H_{f_1}}{H_{f_2}}=\frac{1}{10}$](https://tex.z-dn.net/?f=%24%5Cfrac%7BH_%7Bf_1%7D%7D%7BH_%7Bf_2%7D%7D%3D%5Cfrac%7B1%7D%7B10%7D%24)
or ![$H_{f_2}=10 \ H_{f_1}$](https://tex.z-dn.net/?f=%24H_%7Bf_2%7D%3D10%20%5C%20H_%7Bf_1%7D%24)
Thus the answer is option A). 10