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!

2D kinematic questions

  1. Sep 18, 2012 #1
    1. The problem statement, all variables and given/known data
    Ted Williams hits a baseball with an initial velocity of 120 miles per hour (176 ft/s) at an angle of θ = 35 degrees to the horizontal. The ball is struck 3 feet above home plate. You watch as the ball goes over the outfield wall 420 feet away and lands in the bleachers. After you congratulate Ted on his hit he tells you, 'You think that was something, if there was no air resistance I could have hit that ball clear out of the stadium!'

    Assuming Ted is correct, what is the maximum height of the stadium at its back wall x = 565 feet from home plate, such that the ball would just pass over it?

    You may need:
    9.8 m/s2 = 32.2 ft/s2
    1 mile = 5280 ft

    2. Relevant equations
    Xf=Xi+Vit+0.5a(t^2)


    3. The attempt at a solution
    Horizontal:
    a=0
    Vi=176cos35
    xi=0
    Xf=565

    Vertical:
    a=-32.2ft/s^2
    Vi=176sin35
    Xi=3 ft

    i simply plugged the horizontal values in and solved for t which was 3.918

    i then used t and the vertical components and simply plugged it in and gave me Xf being 151.34ft ft which is wrong.... This is a online grading so they might be picky about the accuracu but i just want to be sure i'm doing the steps right.
     
    Last edited: Sep 18, 2012
  2. jcsd
  3. Sep 19, 2012 #2
    The steps seem OK. The values are off in the last digit: I get 3.919 and 151.35.
     
  4. Sep 19, 2012 #3
    Why are you bumping this?
     
  5. Sep 19, 2012 #4
    if voko's post didn't help, then you should explain why :)
     
  6. Sep 19, 2012 #5
    woops wrong post i bumped LOL. But yea... still giving me me as the wrong answer for some reason...... i think i'll just ask my proff if there's something wrong with the grading system
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: 2D kinematic questions
  1. 2D Kinematics question (Replies: 3)

  2. 2D Kinematics Question (Replies: 6)

Loading...