calculating forces

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watermelonman

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I have a rather large nose weight tied into one of my rockets with kevlar line. I am a little concerned about the forces of certain motors being too great for this configuration. Anyone have the equations involved handy, or some rules of thumb?
 
We need a little more info....

Not sure how you have the weight tied, how much weight what strength kevlar line, was size rocket, what size motor, etc.

Besides the actual motor forces during launch, there is the ejection charge.

Figure you are going to see multiple g's of force, so the weight X g = force on the kevlar.
Figuring out the number of g's depends on the manner factors (plus others) that I already listed....
 
Well, F = ma, where m would be the mass of the object and a would be the acceleration imparted by the motor (to the entire rocket). I have an article on Flight Physics which goes into more detail.

For your example, I agree with les that deployment and landing will be more of an issue that the motor burn because they are much more sudden.
 
Thanks! I can definitely share all of the details, but was mostly looking for equations in hopes of doing the real work myself.

This is a 6lb rocket, before the 4lb weight was added. I know that normally deployment and landing are the sudden forces but I happen to be using a K2045 which appears to be rather sudden as well.

I have test flown on some small J motors, where both deployment and landing were fine.
 
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