Finding spring constant k in N/m

[jimko]

Homework Statement

The graph of displacement vs. time for a small mass at the end of a spring is shown in the figure. At t = 0, x = 0.43 cm. If m = 16.9 gram, find the spring constant, k.

T = 0.69 seconds

Homework Equations

F = kx

The Attempt at a Solution

mg=kx

(.0169 kg)(9.8 m/s^2) / (.0043m) = 38.56

Which is wrong. Is there another way to solve this problem that I'm not seeing?

 

[bsrishu]

graph please

 

[jimko]

There we go.. can you see that?

 

[bsrishu]

if you have done SHM then:
T=2pi(m/k)^1/2
From the graph T=0.69sec.
After putting the i am getting k=1.39 N/m.
Am I correct.
Can u tell how to upload picture(from mobile). I am new here