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## Homework Statement

If the following Force v. Displacement graph is for a 9.9kg object and it's initial velocity is 28.6 m/s the what is its velocity at 30 m?

## Homework Equations

I am not certain that i am even using the right equations with this but:

W = fd

KE = 1/2mv(final)^2 - 1/2mv(initial)^2

## The Attempt at a Solution

I thought since W=Fd and work is proportional to kinetic energy, which is

KE=1/2mv(final)^2 - 1/2mv(initial)^2 and i then could substitute in the Fd, making the new equation:

Fd = 1/2mv(final)^2 - 1/2mv(initial)^2

This could then be rearranged to find final velocity:

sqrt { (Fd + 1/2mv(initial)^2) / 1/2m } = v(final)

Only the issue is that i do not know which F to use to find the final velocity at d=30meters. Because if i use the 0 the whole Fd cancels out, and i get the wrong answer. But if i use 100 then it comes out as larger than the initial velocity, which is not possible as it is losing speed due to lack of force after 20 meters.