C 12 physics problem: Water speed and duration of impact

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The discussion revolves around a physics problem involving a garden hose nozzle that shoots water vertically upward before it falls back to the ground. The initial question concerns calculating the speed of the water as it leaves the nozzle, with one participant arriving at a speed of 4.2 m/s, while another claims the correct speed is 9.05 m/s, achieved through a simpler calculation. Participants emphasize the importance of understanding the physics behind the problem rather than just obtaining the correct answer. The conversation highlights the relationship between the height the water reaches and the duration of its impact on the ground. Overall, the focus is on solving the problem accurately and explaining the underlying principles.
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I have the Giancoli text and I ran across this lvl III problem (pg 44 , #48) on the hmwk:

Suppose you adjust your garden hose nozzle for a hard stream of water. You point the nozzile vertically upwatd at a height of 1.5 m above the graound. When you quickly move the nozzle away from the vertical, you hear the water striking the ground next to you for another 2.0 secs. What is the speed as it leaves the nozzle

the drawing is something like this. The hose is the dash, the water is the x, the side dash is the length above the ground:

then it comes curving down in a parabola, the hose is 1.5 m from the ground

x
x
x
[ ]
[ ]
[ ]
[ ]
|
| > 1.5 m
|

- sorry for the bad illustration. I can't get it to work right

- I got 4.2 m/s after a bunch of algebra, can someone tell me if that's right and work it out possibly?
 
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faceblah said:
I have the Giancoli text and I ran across this lvl III problem (pg 44 , #48) on the hmwk:

Suppose you adjust your garden hose nozzle for a hard stream of water. You point the nozzile vertically upwatd at a height of 1.5 m above the graound. When you quickly move the nozzle away from the vertical, you hear the water striking the ground next to you for another 2.0 secs. What is the speed as it leaves the nozzle

the drawing is something like this. The hose is the dash, the water is the x, the side dash is the length above the ground:

then it comes curving down in a parabola, the hose is 1.5 m from the ground

x
x
x
[ ]
[ ]
[ ]
[ ]
|
| > 1.5 m
|

- sorry for the bad illustration. I can't get it to work right

- I got 4.2 m/s after a bunch of algebra, can someone tell me if that's right and work it out possibly?
Why don't you explain how you got it? What is the height that the water reaches? How is that related to the speed of the water?

AM
 
lol...it was really complicated, but umm someone else got 9.05 m/s and they did it in like one line. Iono thought because it was one of the last problem on that page so i don't think it can't be solved in like 1 line
 
faceblah said:
lol...it was really complicated, but umm someone else got 9.05 m/s and they did it in like one line. Iono thought because it was one of the last problem on that page so i don't think it can't be solved in like 1 line
So you were guessing? You get most of your marks for being able to explain the physics. the right answer is worth very little if you can't explain how you got it.

What determines how long the water continues to hit the ground after the water stops going up? How does that related to the speed of the water?

AM
 
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