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usamo42j

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## Homework Statement

An angler hangs a 4.50-kg fish from a vertical steel wire and 5*10^-3 cm^2 in cross-section area. The upper end of the wire is securely fastened to a support.

a) Calculate the amount the wire is stretched by the hanging fish.

The angler now applies a force F to the fish, pulling it very slowly downward by 0.500 mm from its equilibrium position.

Calculate

b)Work done by gravity

c) Work done by the force F

d) Work done by the force the wire exerts on the fish

e) Change in elastic potential energy

## Homework Equations

Young's modulus = Tensile stress/tensile strain=F/A*l0/Δl

Newton's laws (?)

## The Attempt at a Solution

Young's modulus for steel is 20^10 = 4.5g/(5*10^-7)*1.5/Δl and solve for Δl

Then the work done by gravity is 4.5g*0.500/10^3

But it doesn't seem like there is enough information about the forces to answer c) and d)... I tried setting the force equal to the weight, but that didn't work.

Help is appreciated. ~