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Drinking Fountain Lab

  • Thread starter hn13
  • Start date
  • #1
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Homework Statement



Calculate the initial velocity at which water exits the spout of a common drinking fountain

Homework Equations



V1x=V1cosΘ Θ=tan-1 (opp/adj)
V1y=V1sinΘ

V2^2=V1^2+2ad

The Attempt at a Solution



I measured the total distance travelled by the water in the x-direction (dx), and I got 13.2 cm. I also measured the maximum height and got 8.8cm. I used the kinematic formula (V2y^2=V1y^2+2aydy), so I had:

V2y^2=V1y^2+2aydy
0=V1y^2+2(-9.8)(8.8)
V1y= 13.3 m/s

I calculated the angle using the tan formula, so I got:
Θ=tan-1(opp/adj)
Θ=tan-1 (8.8/6.6)
Θ=53 degrees

Since I had the angle and V1y, I used these two to get V1x:

tanΘ=V1y/V1x
V1xtan53=13.3
V1x= 9.89m/s

Then I just used the pythagorean theorem to solve for V1. Would my method be correct?
 

Answers and Replies

  • #2
SteamKing
Staff Emeritus
Science Advisor
Homework Helper
12,798
1,666
You are careless with your units and have omitted them from your calculations.
What are the units of g? What units were your measurements of the stream made in?
 

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