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Rocket acceleration/time problem?

  1. Sep 8, 2011 #1
    1. The problem statement, all variables and given/known data

    A 200kg weather rocket is loaded with 100kg of fuel and fired straight up. It accelerates upward at 34m/s^2 for 32s , then runs out of fuel. Ignore any air resistance effects.

    how long is the rocket in the air?
    2. Relevant equations
    d=Vit +1/2at^2
    Vf=Vi + at
    and possibly Vf^2=vi^2 +2ad

    3. The attempt at a solution

    Ok so i calculated the rockets average velocity which is 78km (i have to use 2 sig figs), don't know if thats revenant though.

    Also is the weights even a part of the problem? or is it a trick?

    I figured out that this problem has 2 parts, the part where its accelerating and the one where the fuel runs out but its still going upward.

    from the question it says 32s (which is for the first part) so do i have to find the distance for the 2nd part and just add them? some help would be very welcome :)
  2. jcsd
  3. Sep 8, 2011 #2
    Calculate how far up it'll be once it runs out of fuel then use d=h +1/2at^2 (h being the height)
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