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 Question Speed/Time

  1. Nov 25, 2012 #1
    1. The problem statement, all variables and given/known data

    A ball player hits a home run, and the baseball just clears a wall 20.9 m high located 131.0 m from home plate. The ball is hit an an angle of 35° to the horizontal, and air resistance is negligible. Assume the ball is hit at a height of 0.9 m above the ground.
    (a) What is the initial speed?
    m/s
    (b) How much time does it take for the ball to reach the wall?
    s
    (c) Find the components of the velocity and the speed of the ball when it reaches the wall
    vy,f = m/s
    vx,f = m/s
    vf = m/s

    2. Relevant equations
    vi(intial velocity)


    3. The attempt at a solution
    I got 8.5 seconds for the time but thats apparently not right and it's prohibiting me from further progress.
     
  2. jcsd
  3. Nov 25, 2012 #2

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    Welcome to PF!

    Hi Debate123! Welcome to PF! :wink:

    Show us your full calculations, and then we'll see what went wrong, and we'll know how to help! :smile:
     
  4. Nov 25, 2012 #3
    Dx+Vxi*t
    DX=Vx*CoS35.t
    !3!+Vxcos35.tw
    Vi+131?Cos35.tw

    20.9+-4.9t^2+sin35/Cos35+.09
    20.9=-4.9tw2+65.1385/.8191+.09
    20.9=-4.9tw^2+91.727+0.9
    20.9-92.627=tw^2
    tw=sqrt71.727
    tw=8.46(deemed wrong by my webassign)
     
  5. Nov 25, 2012 #4

    tiny-tim

    User Avatar
    Science Advisor
    Homework Helper

    i think you may have entered 113 instead of 131 :wink:
     
  6. Nov 25, 2012 #5
    I still don't know to fix my problem entirely, theres 5 parts and I can't even get 1
     
  7. Nov 25, 2012 #6
    Can someone show me the time so I can finish the problem myself please?
     
  8. Nov 25, 2012 #7
    NVM figured it put by myself
    a) Initial ball speed: 41.7 m/s
    b) Time for ball to reach wall: 3.81 s
    c) x velocity-component: 34.2 m/s
    y velocity-component: -13.4 m/s
    Speed of the ball: 36.7 m/s
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Physics Question Speed/Time
  1. Physics speed question (Replies: 1)

Loading...