work done by spring

[mochabcha]

I have a problem I need help with:
A block 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. What is the position of the block?

[Gokul43201]

What's the problem with the problem ? Draw a force diagram. You know how to calculate the force due a stretched spring...do it.

[mochabcha]

I've tried the formula F(spring) = -kx and got -.08 but thats not the answer.

It seems to me when the mass stops the applied force will equal the spring force

[Tom McCurdy]

next time try posting in the homework help section

[Gokul43201]

And check your sign. Read what the question says about which direction (positive or negative x-direction) the block is pulled.