A garden hose of inner diameter 2 cm carries water at 2 m/s. The nozzle at the end has diameter 0.42 cm. How fast does the water move through the nozzle?
2006-11-03 13:55:27 · 5 answers · asked by Anonymous in Science & Mathematics ➔ Physics
If a molecule of the water is moving at 2m/s through the hose, it is because of the nozzle, not despite it. That molecule travels through the nozzle at 2m/s.
2006-11-03 16:14:15 · answer #1 · answered by merlyn 2 · 0⤊ 0⤋
This problem is about discharge. We take this subject up in hydraulics. The discharge is given by the formula, Q=av, where a is the area of the hose or nozzle, and v the respective velocity. The discharge in the hose equals the discharge in the nozzle. Therefore,
(pi*2^2/4)*2=(pi*0.42^2/4)*v
pi cancels out. the 4 in the denominator also cancels out. Actually you also have to convert cm to m, but in this problem the conversion factor cancels out as well. What remains are:
2^2*2=0.42^2v
8=.176v
v=8/0.176
=45.4m/s
2006-11-03 22:19:39 · answer #2 · answered by tul b 3 · 0⤊ 0⤋
The nozzle helps to increase the velocity as water leaves it and thus there will be a reduction in the pressure and increase in velocity. In this case the water would have attained a velocity of 200/21=9.5 m/sec not taking into account the surface roughness.
VR
2006-11-03 22:00:57 · answer #3 · answered by sarayu 7 · 0⤊ 0⤋
You dont lower the pressure, you only control the volume
Note, Unless you have a built in pressure regulator, which most people dont
2006-11-03 22:04:23 · answer #4 · answered by RatBastard 1 · 0⤊ 0⤋
is this homework? lol!
good luck with that
2006-11-03 22:18:52 · answer #5 · answered by Anonymous · 0⤊ 0⤋