Gr12 Energy Prob: Solving for Waterfall Speed at Top

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The discussion centers on solving a physics problem regarding the speed of water at the top of Della Falls, given its speed after falling 12% of the height. The user applies the conservation of energy principle, setting up the equation to relate the initial and final energies. They calculate the initial speed, v1, using the heights and final speed, v2, but arrive at a value of 7.4 m/s, while the textbook states it should be 5.0 m/s. The user seeks confirmation on their approach and calculations, indicating a potential discrepancy between their result and the expected answer. The conversation highlights the importance of correctly applying energy conservation in physics problems.
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Homework Statement


"The highest waterfall in Canada is Della Falls in B.C., with a change in elevation of 4.4*10^2m. When the water has fallen 12% of its way to the bottom, its speed is 33 m/s. Neglecting air resistance and fluid friction, determine the speed of the water at the top of the waterfall."

RTF: V1
V2 = 33 m/s

(need help on this part, tell me if I'm doing it right) I pick the ground as a point of reference, so:
y1 = 4.4*10^2 m
y2 = (4.4*10^2)(1-0.12)

Homework Equations



Et1=Et2 (Conservation of Energy)

The Attempt at a Solution



Et1=Et2
1/2mv1^2 + mgy1 = 1/2mv2^2 +mgy2
(mass cancels out)
v1 = sqrt( 2 ( 0.5v2^2 + g(y2-y1)))

I plug everything in and I get 7.4 m/s, book says 5.0 m/s
 
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guess I'm right then? Thanks
 
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