The relationship between time taken per oscillation and mass

AI Thread Summary
The experiment measures the time taken per oscillation of a ruler with attached weights, revealing a curved relationship between mass and time on a plotted graph. When the time values are squared, the graph becomes linear, suggesting mass is proportional to the inverse square of time. The discussion explores the mathematical relationship involving angular velocity and oscillation force, leading to the conclusion that mass is proportional to the square of the period (t²). Some confusion arises from notation choices, particularly in representing displacement and amplitude. Overall, the reasoning is mostly correct, though clearer notation is recommended for better understanding.
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In an experiment, a ruler is connected to the table and some weights are bounded to one end of the ruler. The ruler is then flicked and the time taken per oscillation is measured.

I have plotted a graph with the data I have collected, with the mass on the y-axis and time on x-axis. The graph produced appears to be a curve. I have tried altering the values on the x-axis; I have squared it, 1 over the square of it, square rooted it, and I found that the graph becomes linear when the values are squared. So the mass should be proportional to 1 over the square of the time taken.

I have tried finding out a mathematical relationship for this, but I am not sure if this is correct or not.

Well, if we make w=angular velocity, then w=θ/t, with θ being angular displacement and t being the time period. Since θ belongs in a circle, then it is safe to say that w=2π/t (?)

Also, if the force of an oscillation is proportional to -displacement (x), then it is true to say that F=-kx, with k being a constant.

Since F also = ma, then ma=-kx.

According the the simple harmonic wave equation for acceleration is a=-xw2sinwt. Since the formula for displacement(x) = x sinwt and a=-w2(x sinwt), then a=-xw2

So ma=-kx will become m(-xw2)=-kx, then using some algebra, m=k/w2. Since w=2π/t, then m=kT2/4π2.

Since k/4π2 is a constant, I can ignore that and say m is proportional to t2.

Is my reasoning true? I feel like I am wrong in quite a few spots.

Thanks for helping
 
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Yes, this is essentially correct, but you take a few confusing steps because of a poor choice of notation. For instance, you use x to represent displacement as well as the amplitude (or maximum displacement). You should use different symbols for these - it will help keep things clear for you as well.

You write: x = x sin(wt), which looks nonsensical.

Better would be something like: x = A sin (wt), or x = x0 sin (wt).

Also, next time, a question like this is better suited for the Intro Physics section.
 
Thank you.
 
Yes thank you very much! It is so helpful!
 
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