- #1
leehufford
- 98
- 1
Hello,
Recently I saw a youtube video of the Apollo 11 launch with time and velocity data. I took data in 5 second increments and put the data in my graphing calculator. I used a quadratic regression to come up with a velocity time function.
I then differentiated this function to come up with an acceleration time function, and for the first 22 seconds I have a negative acceleration. Where did I go wrong?
My velocity function from quadratic regression:
v(t) = 0.1368t^2 - 5.9846t + 102.863
Then differentiating for a(t):
a(t) = 0.2736t - 5.9846
I tried removing the point (0,0) so I could do an exponential regression, but this fits the data worse and gives a nonzero acceleration at t=0...
So either I am using the wrong regression type or the data was bad. Is the launch simply too complex to fit into a nice differentiable function like this? I just thought it would be cool to have a handle on the types of acceleration experienced during this historic achievement. If you'd like me to post the data I would be happy to. Thanks in advance,
Lee
Recently I saw a youtube video of the Apollo 11 launch with time and velocity data. I took data in 5 second increments and put the data in my graphing calculator. I used a quadratic regression to come up with a velocity time function.
I then differentiated this function to come up with an acceleration time function, and for the first 22 seconds I have a negative acceleration. Where did I go wrong?
My velocity function from quadratic regression:
v(t) = 0.1368t^2 - 5.9846t + 102.863
Then differentiating for a(t):
a(t) = 0.2736t - 5.9846
I tried removing the point (0,0) so I could do an exponential regression, but this fits the data worse and gives a nonzero acceleration at t=0...
So either I am using the wrong regression type or the data was bad. Is the launch simply too complex to fit into a nice differentiable function like this? I just thought it would be cool to have a handle on the types of acceleration experienced during this historic achievement. If you'd like me to post the data I would be happy to. Thanks in advance,
Lee
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