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Exuro89
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Work energy question. Fish on a spring.
Question has been changed as I figured it out. New one is on fish and springs
If a fish is attached to a vertical spring and slowly lowered to its equilibrium position, it is found to stretch the spring by an amount d.
If the same fish is attached to the end of the unstretched spring and then allowed to fall from rest, through what maximum distance does it stretch the spring? (Hint: Calculate the force constant of the spring in terms of the distance d and the mass m of the fish.)
Work Energy Theorem
F=-kx
I understood the hint, in which the force constant is k = (mg)/d
Now I need to come up with a work energy equation. Energies would be potential spring and gravitational. Initial would be only gravitational as the spring hasn't been stretched. The final energy should be all spring. So the equation would be
0 = -mgh + 1/2kd^2 or mgh = 1/2kd^2
h is the maximum distance the spring will go. I need to replace k with (mg)/d so I only have those few variables, so
mgh = 1/2(mg/d)d^2
mgh = 1/2mgd
h = 1/2d
Well I'm pretty sure this is wrong. The total distance should be greater than the stretch no? What is it that I'm doing incorrectly?
Question has been changed as I figured it out. New one is on fish and springs
Homework Statement
If a fish is attached to a vertical spring and slowly lowered to its equilibrium position, it is found to stretch the spring by an amount d.
If the same fish is attached to the end of the unstretched spring and then allowed to fall from rest, through what maximum distance does it stretch the spring? (Hint: Calculate the force constant of the spring in terms of the distance d and the mass m of the fish.)
Homework Equations
Work Energy Theorem
F=-kx
The Attempt at a Solution
I understood the hint, in which the force constant is k = (mg)/d
Now I need to come up with a work energy equation. Energies would be potential spring and gravitational. Initial would be only gravitational as the spring hasn't been stretched. The final energy should be all spring. So the equation would be
0 = -mgh + 1/2kd^2 or mgh = 1/2kd^2
h is the maximum distance the spring will go. I need to replace k with (mg)/d so I only have those few variables, so
mgh = 1/2(mg/d)d^2
mgh = 1/2mgd
h = 1/2d
Well I'm pretty sure this is wrong. The total distance should be greater than the stretch no? What is it that I'm doing incorrectly?
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