I have previosly asked these questions, but the answerers don\'t answer my comme
ID: 1306050 • Letter: I
Question
I have previosly asked these questions, but the answerers don't answer my comments when I tell them that it's incorrect and therefore keep giving me the incorrect answers. I would appreciate any help. Thank you.
1. The pressure in the atmosphere is not constant, but fluctuates as the weather changes. If the pressure outside a window drops by 4% while the pressure inside does not change, what is the force on the window? Assume the area of the window is 1.9 m2. (The positive direction is toward the inside of the window. Indicate the direction with the sign of your answer. Assume that the initial pressure inside and outside the window is initially 1 atm.)
Previous INCORRECT answers= 1.82x10^5 N
2.When a person is given intravenous fluid, the bag containing the fluid is typically held about 1.1 m above the person's body. If the pressure in this fluid is just barely able to push the fluid into the person, what is the pressure in the person's blood? (The density of the intravenous fluid is approximately that of water.)
PREVIOUS INCORRECT ANSWER GIVEN: 1.08X10^4
3.Consider a rectangular swimming pool of depth 1.9 m with a width and length of 13 m. What is the force exerted by the water on one of the sidewalls of the pool?
PREVIOUS INCORRECT ANSWER GIVEN: 2.30X10^5 N
4.An engineer is given the job of designing the water system for a tall building. He decides to locate the pumps at ground level and feed the entire building from there. If the top floor of the building is 250 m above ground level, what must the pressure be at pump level?
PREVIOUS INCORRECT ANSWER GIVEN: 2.45 Pa
Previous INCORRECT ANSWER: 12.33 Pa
Explanation / Answer
Number 1)
The pressure difference is .04(1.013 X 105) = 4052 Pa
P = F/A
F = PA = (4052)(1.9) = 7699 N
Number 2)
P = Patm + pgh =
P = (1.013 X 105) + (1000)(9.8)(1.1)
P = 1.12 X 105 Pa
Number 3)
P = F/A
F = PA = .5pghA
F = (.5)(1000)(9.8)(1.9)(13)(13)
F = 1.57 X 106 N
Number 4)
P = Patm + pgh
P = 1.013 X 105 + 1000(9.8)(250)
P = 2.55 X 106 Pa
(If your key does not like that answer, subtract the atmospheric pressure and get 2.45 X 106 Pa)
Number 5)
We need the velocity
V = Av
2.1 X 10-7 = (pi)(.0022)2(v)
v = .01381 m/s
P = .5pv2
P = (.5)(1000)(.01381)2
P = .0954 Pa (9.54 X 10-2 Pa)