stumped by the elasticity difference between two calculations

Question

nincompoop · Answer

would someone be so kind to enlighten me on almost 200% difference between two calculations.

nincompoop · Answer

attachment

nincompoop · Answer

the same spring were used in B & C

anonymous · Answer

I like the watermark ^_^

nincompoop · Answer

the rest, I do not like LOL

anonymous · Answer

graphs need units forever and for always!   0_0  :/

nincompoop · Answer

yeah the unit is on the header

anonymous · Answer

This looks profo enough that I figured they were somewhere ^_^  Question: what are you graphing in part C?  none of the numbers in your table correspond to a negative x value, yet one exists.

anonymous · Answer

oooo, nm, I'm a dumb

nincompoop · Answer

the table C is a measurement of oscillation - period, but even so, the k would have to be relatively close to the k=x/f in table B not a whopping 200% difference. Unless the additional pull (extra elongation) on the weight to create an oscillation increases the error margin by a great magnitude.

anonymous · Answer

why doesn't k = f/x?

$$ \sum F = -mg-xk=o \ \ ; \ \ k=mg/x$$

am I double crazy?

nincompoop · Answer

typo
it is k=f/x

anonymous · Answer

oh thank god.  ok.

nincompoop · Answer

F = -kx

anonymous · Answer

your slope on b is definitely using x/mg   ;/

nincompoop · Answer

you know the lab manual wanted to use the displacement as y and mg as x 
which I thought was incorrect, but following hook|dw:1383295334067:dw|