i’m hoping someone can help me. i’ve worked on this problem for 2 days and can’t seem to get the answer. i’m stuck and need some help.
i need to calculate the max altitude a model rocket will reach. the total rocket mass before it blasts off is 46g and the mass after it lands is 41g (since engine loses mass). it’s an Estes A8-3 engines that has a total impulse of 2.5 N seconds, an ave thrust of 7.7 N, and a time delay of 3 sec (# seconds between end of thrust phase and time the rocket will reach max altitude).
our teacher told us to ignore drag, air resistance, and wind. the only forces we’re to use are the engine thrust and gravity.
i know i need to use newton’s 2nd law (F=ma) but i’m not sure how to use it here. are there other formulas that i also need? i’m not sure what to do with the thrust, impulse, masses and times and how they fit into the 2nd law formula. i’m also not sure how to calculate the max height once i have the force.
thanks!
i think there are 2 phases i need to work with and those are the initial phase when the rocket engine is burning and the coasting phase after the engine burns out while the rocket still continues to go up. i probably need to add those together to get the max height. i’m just not sure how to calculate either of those and could really use some help.
can someone help? thanks.
