Pendulum EPI

[YellowTongue]

So I'm doing my EPI next week on "Factors that affect the period of a simple pendulum".

However, I'm not quite sure how to use my data. I figure that there will be three variables: the time (independent) and the vertical and horizontal displacement (dependent variables). How should I graph this. In theory, I believe that if I graph the two dependant variables I will get a Sine Graph, however this is ignoring time; should I use the magnitude of the displacement and plot this against time?

What do I do?

[GGWP VCAA]

So I'm doing my EPI next week on "Factors that affect the period of a simple pendulum".

However, I'm not quite sure how to use my data. I figure that there will be three variables: the time (independent) and the vertical and horizontal displacement (dependent variables). How should I graph this. In theory, I believe that if I graph the two dependant variables I will get a Sine Graph, however this is ignoring time; should I use the magnitude of the displacement and plot this against time?

What do I do?

Our teacher made us draw a T vs L^0.5 (square root L) graph, to show the linear relationship (from the actual equation) and also a Tvs L graph to compare and contrast. The graphs you draw for the EPI should reflect the prac work and the variables that you have altered( ie length, drop height, mass of weight etc.). As well as this you should explain the results you obtained (for example why did the weight alter/not alter your pendulum etc.)

PS. Why are you doing unit 3 work now, during Unit 4?

[lzxnl]

Using the small angle approximation, the angle made by the pendulum with respect to the vertical is a sinusoidally varying function of time with an amplitude-independent frequency. As the pendulum has the same length the whole time, the vertical and horizontal displacements should satisfy Pythagoras's theorem, depending on how they are defined, so their plot would be a circle. That's not fun.

Plotting the length against the period to some power is the only really interesting plot
You could even plot log T against log length to confirm that it is a square root relationship. The gradient is the power by log laws.