YAPhysicsT: Finding the force of a spring

[Ricemarine]

I'm pretty lost on how to go about this.

-A block of m lies on a horizontal frictionless surface and is attached to one end of the spring(which the spring is frictionless & massless)
-The block is initially at rest where the spring is unstretched(x=0) when a constant horizontal force in the x direction is applied to it.
-A graph shown shows a parabola with these key points with the distance in the x axis and the resulting kinetic energy in the y axis.
- when x=0, the kinetic energy = 0J
- when x = 1, the kinetic energy = 4.0J
- when x = 2, the kinetic energy = 0J

What is the magnitude of F, and the value of k (the spring constant)?

What I tried doing is plugging the kinetic energy at x=1, since that was the peak. So therefore

Work = -0.5kx^2
=
4.0J = -0.5k(1)^2
=
4.0J = -0.5k
=
K = -8J

But I think I'm going about this wrong.....

Thanks for those that looks.

 

[needalife]

ahhh... i miss those days...

 

[Epic Fail]

YAHWT

 

[Ricemarine]

Originally posted by: needalife
ahhh... i miss those days...

community college or high school?