Posted by Mackenzie on Thursday, July 22, 2010 at 3:35pm.
I have to design a procedure which will allow me to calculate the applied force(thrust) of a stomp rocket. We are allowed to use tools to find measurements. So far, I have calculated the height that the rocket reached (22.5) m using trig. (right angle triangle where one angle is 66 degrees and the adjacent length is 10m), the mass of the rocket (14.29g) and the mass of the person stomping on the rocket (104 pounds) I now don't know how to calculate the applied force of thhe stomp rocket used to thrust/accelerate it through the air. Help please!

Physics  bobpursley, Thursday, July 22, 2010 at 4:11pm
This is simple with a CBL equipment (computer based lab), it has a force detector. IT measures force vs time. You put the "rocket in a stand, with a upper block preventing if from leaving, put the force detector at the top, and "launch" the rocket. THe computer measures force vs time, graphs it, and integrates it to give total impulse. Ask your teacher if this equipment is available.
Failing that, any measurement is pretty weak. You need not only force, but time (rockets gain impulse (force*time)).
The pressure in the launch tube changes very rapidly, I doubt if you could read it on a pressure gauge.
Have you tried measuring the initialvelocity of the rocket with high speed camera, your camera in movie mode probably can help in that, frame by frame. That intial velocity is a sure measure of the impulse given to the rocket.