Calculating Final Velocity

  1. Question is a golf ball is dropped from a height of 78m assuming gravity is 9.8 m s, What is the velocity of the ball after the first 10m.

    I assume the equation to use is [tex]v^2=u^2+2ax[/tex]

    v = Final velocity
    u = Initial Velocity
    a = Acceleration
    x = Displacement

    So I plug in [tex]v^2 = 0+2(9.8ms)(10.0)[/tex]

    Now according to the answer sheet V should be 14.0 m s but no matter how I plug this in I cant seem to get the right answer.

    I think the problem is the way I am actually doing the math so if someone could perhaps step threw the maths so I can see where I went wrong.

    Thanks for any help
    1. The problem statement, all variables and given/known data



    2. Relevant equations



    3. The attempt at a solution
     
  2. jcsd
  3. you shoudnt only learn about plugging values into the formula, you should learn the physical meaning of the formula!!!!!!!!!! THAT IS VERY IMPORTANT I got 14 using the EXACT equation above, I believe you have made a careless mistake.
     
  4. HallsofIvy

    HallsofIvy 40,372
    Staff Emeritus
    Science Advisor

    No, no one can possibly tell you what you did wrong, because you haven't told us what you did! The equation you have, v2= 2*9.8*10 is correct and gives v= 14 m/s. Apparently you made a mistake in the arithmetic, although it seems rather elementary to me! Since you didn't show what you did or tell us what answers you got, I can't tell if it was something as simple as forgetting to take the square root.
     
  5. Solved

    How embarrassing, oerg you where spot on I forgot to take the square of the answer I think I have been working at this too long tonight :rolleyes:.

    Thanks Again
     
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