- #1

- 31

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vi = ?

vf = 0 m/s (can i assume this)

a = -9.8 m/s^2

d = 1.3 m

t = ?

use vf^2 = vi^2 + 2ad to find vi

0 = vi^2 + 2(-9.81)(1.3)

but can't take the square root of a negative number?? this is where i am stuck...

- Thread starter petuniac
- Start date

- #1

- 31

- 0

vi = ?

vf = 0 m/s (can i assume this)

a = -9.8 m/s^2

d = 1.3 m

t = ?

use vf^2 = vi^2 + 2ad to find vi

0 = vi^2 + 2(-9.81)(1.3)

but can't take the square root of a negative number?? this is where i am stuck...

- #2

OlderDan

Science Advisor

Homework Helper

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There is no square root of a negative number required. Isolate the vi^2 term

- #3

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so vi = 5.05 m/s.. is this right?

- #4

OlderDan

Science Advisor

Homework Helper

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Correct. It is a bit unrealistic though. That would be correct if the salmon could jump vertically to reach the top, which of course is not possible. But it is the correct answer to the question as it was asked.petuniac said:so vi = 5.05 m/s.. is this right?

- #5

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thanks for your help!

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