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Okay, Here's the problem

The block in Figure 7-11a (Figure not important) lies on a horizontal frictionless surface and is attached to the free end of the spring, with a spring constant of 35 N/m. Initially, the spring is at its relaxed length and the block is stationary at position x = 0. Then an applied force with a constant magnitude of 2.8 N pulls the block in the positive direction of the x axis, stretching the spring until the block stops. Assume that the stopping point is reached. (a) What is the position of the block? (b) What is the work that has been done on the block by the applied force? (c) What is the work that has been done on the block by the spring force?

(a) I drew a free body diagram and it seems like when the block stops the spring force catches up to the applied force counteracting it and stopping the motion of the block. So, Hooke's law states that F(spring) = -kx; since F(spring) = F(applied) --> F(applied) = -kx.

I crunched those numbers and got -.08 which made sense because the applied force is going to be positive [f(s) is negative in Hooke's law and x being a negative number will cancel the negatives].

BUT THAT'S WRONG what's the problem!!! :surprised

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# Homework Help: Position of a spring

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