1. Not finding help here? Sign up for a free 30min 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!

Altitude in time

  1. Sep 9, 2015 #1
    1. The problem statement, all variables and given/known data
    A spaceship lifts off vertically with constant acceleration and reaches a speed of 340 km/hin 1.1 min .
    What is the ship's altitude at t = 66 s ?
    Express your answer to two significant digits and include the appropriate units.
    2. Relevant equations
    xf = xi + v*delta t

    3. The attempt at a solution
    6233.04 m
     
  2. jcsd
  3. Sep 9, 2015 #2
    Please show us your work.

    Chet
     
  4. Sep 9, 2015 #3
    You need to find the acceletion of the spaceship,after this put this data in equzion that describe his state according the time including acceleration parameter,
    Can you find this equzion? :wink:
     
  5. Sep 9, 2015 #4
    I convert 340 km/h to 94.44 m/s and 1.1 min to 66 s.
    I plug the known data to the equation:
    xf = 0 + (94.44)(66)
    xf = 6233.04 m
     
  6. Sep 9, 2015 #5
    You plugged in the final velocity, but was it travelling with that velocity the whole time? What was the average velocity, given the acceleration was constant?

    Chet
     
  7. Sep 9, 2015 #6
    This equation doesn't describe the body in acceleration...
     
  8. Sep 9, 2015 #7
    a = 94.44/66 = 1.43 m/s^2
    xf = xi + vi*t + 1/2at^2
    xf = 0 + (94.44)(66) +1/2(1.43)(66)^2
    xf = 9347.58 m
     
  9. Sep 9, 2015 #8
    Thats right!!! :oldbiggrin:
     
  10. Sep 9, 2015 #9
    So to express the answer in two sig figs, it should be 9.3 x 10^3 m?
     
  11. Sep 9, 2015 #10
    I submit the answer but it is still incorrect according to Mastering Physics
     
  12. Sep 9, 2015 #11
    This is incorrect. The initial velocity is zero. Only the 3rd term should be in there. Alternately, the average speed is (94.44)/2 = 47.22 m/sec, so the distance should be half your original answer 6233/2 = 3117 m. Either way, you will get the same answer.

    Chet
     
  13. Sep 9, 2015 #12
    I would check my answer again. Thanks!
     
  14. Sep 9, 2015 #13
    The initial velocity is zero due to the fact that it say to us that spaceship accelerate from zero to 340 km/h
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Altitude in time
  1. Maximum altitude (Replies: 7)

  2. Change in altitude (Replies: 1)

  3. Finding Altitude (Replies: 1)

  4. Determine altitude (Replies: 9)

Loading...