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!

Physics 11, kinetic energy problem

  1. Dec 20, 2006 #1
    Hey if anyone could help me work through a couple of problems that would be great!:smile:

    1. The problem statement, all variables and given/known data

    It is not uncommon during the service of a professional tennis player for the racquet to exert an everage force of 150.0N on the ball. If the ball has a mass of 0.060kg and is in contact with the strings of the racquet for 0.030s what is the kinetic energy of the ball as it leaves the racquet? Assume the ball starts from rest


    2. Relevant equations

    Ek=1/2mv^2

    3. The attempt at a solution
    I'm not sure really where to start here....
     
  2. jcsd
  3. Dec 20, 2006 #2

    radou

    User Avatar
    Homework Helper

    A hint: impulse.
     
  4. Dec 20, 2006 #3
    Well, you know what you'll need to find Kinetic Energy--mass and velocity. You're given mass. Can you think of any other equations that might help you find velocity?
     
  5. Dec 20, 2006 #4
    what do i do once i've figured that out?
     
  6. Dec 20, 2006 #5
    d=vt but i don't have a distance either
     
  7. Dec 20, 2006 #6
    Once you've figured what out?
     
  8. Dec 20, 2006 #7
    oh my god i think i got it, will someone let me know if i got it right, just let me work it out.
     
  9. Dec 20, 2006 #8

    radou

    User Avatar
    Homework Helper

    There is no need to create so many posts. :wink:
     
  10. Dec 20, 2006 #9
    i got 169J
     
  11. Dec 20, 2006 #10
    Looks OK to me, whose brain is fried!
     
    Last edited: Dec 20, 2006
  12. Dec 20, 2006 #11

    cristo

    User Avatar
    Staff Emeritus
    Science Advisor

    That's correct.
     
  13. Dec 20, 2006 #12
    p=Ft
    p=150(0.030)
    p=4.5

    p=mv
    4.5=(0.06)(v)
    v=75m/s

    Ek=1/2m^2
    Ek=1/2(0.060)(75^2)
    Ek=169J
     
  14. Dec 20, 2006 #13
    Ok i have a couple of other question so if anyone wants to stick around and help...?
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Physics 11, kinetic energy problem
Loading...