We have some data for a rocket test, and I have plotted thrust against time.
To find the total impluse, we were told to find the area under the thrust graph. But I am a little confused about something.
I defined my zero time as the time the thrust started to increase, but for approx. half a second, the thrust stays at around 1.25 before increasing to 1.75 for the rest of the burn.
What is the reason for this? and is this included as part of the burn time? or does the burn start when the thrust reaches its peak.
Also, the rocket did have a purple flame for a little while before the rocket started properly, so i thought this might be a reason, but i am unsure.
If it is important, it was a hybrid rocket motor, with a solid fuel and Nitrous oxide as an oxidisor
Thanks in advance for any help anyone can give