What is the relationship between force and time in simple harmonic motion?

[Meamour]

For the lab I have to find the spring constant and how force relates to time with simple harmonic motion. To find the spring constant, I used hooke's law and compared different added masses to the stretch from the equilibrium position. When I graphed that, the slope was the spring constant since F= K*X. Using logger lite, I added a one kg mass to the spring I was using and made it oscillate. The vernier quest and the logger lite program produced a Force vs. Time graph. I need to create a theoretical Force vs. time graph (using the time intervals) and manipulate it so that one of the parameters is the spring constant. i will then proceed to compare that to the spring constant found at the beginning.

I am having trouble figuring out how to manipulate the equations. What is the force? I thought it was the weight but that doesn't make sense because the force is changing with each oscillation anywhere between 5 and 13 N. I know that the period is equal to 2pi* sqrt(k/m) but I just don't understand what the force is and how to relate it.

 

[sophiecentaur]

What is the force?

Didn't you already graph the Force vs Displacement when you found the K of the spring?

 

[Meamour]

Didn't you already graph the Force vs Displacement when you found the K of the spring?

Yes I did but I can't use that data to find the second spring constant to compare it to the first. I have to figure out how to manipulate my Force vs. Time graph (that I did with the 1kg mass) to figure out the spring constant.

 

[sophiecentaur]

Yes I did but I can't use that data to find the second spring constant to compare it to the first. I have to figure out how to manipulate my Force vs. Time graph (that I did with the 1kg mass) to figure out the spring constant.

Have I missed something here? The spring Constant is a Constant unless you do something to the spring- like shortening it.
Also can you tell me about the "Force vs Time" and the "Theoretical Force vs Time" graphs. How are they different? I think there must be someone that you are not telling us about the experiment because the basics are all about just two or three formulae that are in all the textbooks.