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!

Impulse and momentum problem, I need help

  1. Oct 7, 2013 #1
    A model rocket is constructed with a motor that can provide a total impulse of 27.5 N · s. The mass of the rocket is 0.173 kg. What is the speed that this rocket achieves when launched from rest? Neglect the effects of gravity and air resistance.



    i know that the equation is p=mv (vector based)



    0.173*v =27.5N so how do i find velocity...
     
  2. jcsd
  3. Oct 7, 2013 #2

    NascentOxygen

    User Avatar

    Staff: Mentor

    Hi bchat112000. http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif [Broken]

    0.173 * v = 27.5 N·s

    That's one equation with one unknown. Are you able to isolate that v pronumeral to one side by itself?
     
    Last edited by a moderator: May 6, 2017
  4. Oct 7, 2013 #3
    yes by multiplying by both sides???
     
  5. Oct 7, 2013 #4
    I love this forum by the way, thx for helping people
     
  6. Oct 7, 2013 #5

    NascentOxygen

    User Avatar

    Staff: Mentor

    What is your final answer for velocity?
     
  7. Oct 8, 2013 #6
    i got 4.75
    0.173 times 27.5n
     
  8. Oct 8, 2013 #7
    ok i plugged the formula ..initial v is 0 final v is 27.5 the mass is 0.173
    0+27.5=0.173 This is the formula
    27.5Ns/0.173kg=159
     
  9. Oct 9, 2013 #8

    NascentOxygen

    User Avatar

    Staff: Mentor

    An equals sign requires what is on one side to equal what is on the other.

    That looks better.

    Speed requires both a magnitude and units

    The correct answer is 159 m/sec
     
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: Impulse and momentum problem, I need help
  1. IMPULSE, i need HELP (Replies: 8)

Loading...