Acceleration due to gravity using a compound pendulum experiment

[Superdreamer]

I am required to plot a graph of l(1+L^2/12l^2) on the x-axis and T^2 on the y axis.The graph must be a straight line through the origin.I got the following values for the l values on the x-axis .57,.47,.37,.27,.17 and corresponding values of T^2 2.46,2.52,2.56,3.24,8.12.As you can see my values are totally off and do not give the necessary slope needed to give 9.8 when subbed into the formula g=4pi^2/slope.Please advise on how i would go about changing the values to suit as I'm unable to do the experiment again

the original formula is T=2pi(sqr l/g) (1+L^2/12l^2)

Big L is 1.2m






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[big man]

You should probably just use the results you have now and then comment on what made them so shoddy. Comment on uncertainties in the measurements and methods to improve your experiment. I think lecturers would prefer bad results with evidence that you've thought about the problems than good results.

 

[Milly_S]

the graph you should be plotting is L(T^2) against L^2 This should be approximatly a straight line, and the gradient should give you g, I think...

 

[thamashi]

please tell me the errors that could be occur in the practical compound pendulum...?

 

[asteriatic]

.57, 0.47, 0.37, 0.27, 0.17 are the values of l, and T^2 are the corresponding values for T^2. However, from the formula T=2pi(sqr l/g) (1+L^2/12l^2), it appears that you have used the wrong value for L. L refers to the length of the pendulum, and in the formula it is squared and multiplied by 1/12l^2. If you have used 1.2m for L, then the values for l should be in meters as well, not in centimeters.

To fix this, you can either convert the values of l to meters (multiply by 0.01) or use a different value for L, such as 0.12m. Once you have corrected the values, you should get a straight line with a slope of 4pi^2/g, which should be close to the expected value of 9.8.

If you are unable to repeat the experiment, you can also try to find the error in your measurements or calculations. Make sure that you have accurately measured the length of the pendulum and the time it takes for one full swing. Double check your calculations and make sure you are using the correct units for all values.

In science, it is important to identify and correct any errors in our experiments and data to ensure accurate results. If you are still having trouble, you can seek help from your instructor or a fellow scientist to review your data and calculations.