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!

I need help finding the distance and the time

  1. Jun 12, 2016 #1
    1. The problem statement, all variables and given/known data

    1. A bottle rocket has an engine that accelerates it upward. Then it coasts to its highest point before returning to the ground. Assuming that the engine creates a net acceleration of 30 m/s2 for 0.5 s, how high does it go, and how long does it take to reach the ground again?

    acceleration= 30m/s^2
    time=0.5s


    2. Relevant equations
    v^2-u^2=2ax

    3. The attempt at a solution
    0^2-(15m/s)^2=2(-9.8m/s^2)x
    -225=-19.6x
    -255/-19.6
    x=11.48m
    to get total height i did 11.48m+3.75m=15.23m

    now how do i get velocity for the other question
    v=at
    v=30m/s^2*0.5s
    v=15m/s
    does this work?
     
  2. jcsd
  3. Jun 12, 2016 #2

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    The acceleration isn't 30m/S^2 on the way down. Nor is the time 0.5 seconds.
     
  4. Jun 12, 2016 #3

    OmCheeto

    User Avatar
    Gold Member
    2016 Award

    That's what I come up with.
    I thought the second part of the question was "find: Total time, from launch to landing"
    ????
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted