1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Need help with rocket math problem

  1. Aug 2, 2010 #1
    1. The problem statement, all variables and given/known data
    A rocket is fired upward from earth with initial velocity v measured in m/s. Then maximum height in m is reached by the rocket is given by the function h(v)=Rv^2/2gR-v^2
    Radius is 6.4(10^6)m and acceleration due to gravity g is 9.8m/s^2 (R and g are constants and v is the independent variable. Graph the function denoting all intercepts, asymptotes, and other points of interest.


    2. Relevant equations



    3. The attempt at a solution I used the escape velocity concept. I then plugged in the numbers given into the function. h(v)=6.4(10^6)(11100)^2/2(9.8)^2(6.4)(10^6)-(11100)^2
    Im not sure if this is correct and how to graph with the correct axes.
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. Aug 2, 2010 #2

    eumyang

    User Avatar
    Homework Helper

    Your equation is very hard to read. Either use some more grouping symbols or retype in LaTeX.

    Your equation could be read like this:
    [tex]h(v)=\frac{Rv^2}{2gR} - v^2[/tex]

    or this:
    [tex]h(v)=Rv^{2/2gR} - v^2[/tex]

    or this:
    [tex]h(v)=\frac{Rv^2}{2gR-v^2}[/tex]

    and so on.


    69
     
  4. Aug 2, 2010 #3
    the last equation shown is what I meant...sorry
     
  5. Aug 3, 2010 #4
    so where's the problems in graphing the equation?
    u have the equation, h(v), take the x-axiz for v and y-axis, for h
    But the graph will be a little difficult to sketch with ur hand, so u may take help of some graphing software

    i couldnt get why u needed to use escape velocity concept or something. wat i see the problem, its just a single variable equation that is to be graphed.
    plz clarify if i missd or misundstood something.
     
  6. Aug 3, 2010 #5
    I used the escape velocity because my teacher gave us a hint using that and told me to look that up. So am I right in plugging in the numbers into the function the way i did above? Yeah I am using grapher to graph the equation. I just want to make sure I plug the correct function into the graph.
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook