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!

Impulse momentum questionsplease need some help

  1. Nov 15, 2004 #1
    hi guys im a college junior...taking physics for the first time in my life...its fun...but still tuff...just can i get help with these couple questions..i mean it would be very gracious of any of u to help me out...i know im new and all, but this place...i was just browsing around and it rocked sooo....and

    wow i never new this place existed....i might come here much more often


    question 1: a 3.0 kg body is initially moving northward at 15m/s. Then a force of 15N, towards the east acts on it for 4.0 s (a) At the end of the 4.0 s, whats the body's final velocity? (b) what is the change in momentum during the 4.0 s?


    i know the answers...can you just show me how to work out part A??? i got 60 for part B, and keep getting 25 for part A, but thats not it....

    i would really appreciate this...thank you...illpost the other 3 questions as well ?
     
  2. jcsd
  3. Nov 15, 2004 #2
    The position of three particles written as (x,y) coordinates are, particle 1 (mass 4.0 kg) at (4.0m, 0m); particle 2 (mass 6.0kg) at (2.0m, 4.0m); particle 3 (mass 3.0 kg) at (-1.0m, -2.0) what is the location of the center of mass????


    this one too pleasE?? how do you do it...i have answers...
     
  4. Nov 15, 2004 #3
    A projectile of mass 2.0 Kg approaches a stationary target body at 8.0 m/s. The projectile is deflected through an angle of 90.0 degrees and its speed after the collision is 6.0 m/s. WHat is the speed of the target body after the collision is perfectly elastic????


    any help on how to do this one guyzz??
     
  5. Nov 15, 2004 #4

    ok i solved this one, so dont need it thanks...
     
  6. Nov 15, 2004 #5
    Considering this is propably one of the easiest exercise you can make of newton's second law and constant acceleration, you should really try solving it again. Keywords: Newton's second law and motion with constant acceleration ;)
     
  7. Nov 15, 2004 #6
    brother i am doing it,....the answer i am getting is 35...teacher says it is 25....what am i doing wrong inthe calculations????
     
  8. Nov 15, 2004 #7

    Integral

    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Perhaps, if you showed us your solution, we could help find the error.

    Also, we have a homework help forum, just for this type of post.
     
  9. Nov 15, 2004 #8
    My guess is you are forgetting that the directions of the two velocities are different (first 15m/s to north and second caused by the force is to east).
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?