# Homework Help: Help me put this rocket into orbit! Need a jumpstart!

1. Nov 30, 2009

### joeblack99999

1. The problem statement, all variables and given/known data
Ok so i had all of this typed up and some work typed out and then the page refreshed and i lost it all so this one is going to be shorter and more brief.

I have to create a spreadsheet and graph of altitude vs time and speed vs altitude. My goal is to place a rocket into a circular orbit assuming only 1 stage of launch/flight. Calculate thrust. Typical exhaust velocity is 3,000 m/s. Ignore air drag. Consider acceleration due to gravity and notice its decrease as the rocket ascends. Consider the altitude of orbit and calculate the speed necessary to keep the rocket in orbit. This will be final velocity (which is when mass of fuel = zero) Most likely i will calculate only vertical velocity. Rocket is launched on equator in east direction (speed of earth in east direction is 1440 km/h) Ignore complication of ejecting the payload with initial tangential speed by assuming when the rocket reaches the desired height it magically turns around and the vertical velocity becomes the tangential velocity. Assume the mass of the rocket, fuel, and payload- and the burnout time.

2. Relevant equations
V(escape)=sqrt(2GME/R)
thrust= [(m1v1)-(m2v2)]/(t2-t1)
V(at equator)= 2piR/t = 463.8 m/s
v= sqrt(mew/r)

3. The attempt at a solution
I need a jumpstart to the problem because i really dont know where to start. I am not simply asking for a full solution to avoid doing my work, but maybe simply some info or tips to start me off thinking in the right direction. Im thinking that i will have (delta)v= v - (delta)force of gravity. I am just not sure which other formulas to use for this specific problem and how to start it off. I've been playing with some numbers and equations but can't piece it all together for the whole overall solution.

Last edited: Nov 30, 2009
2. Nov 30, 2009

### joeblack99999

bump- does nobody know what equations i would need to put something into orbit?