Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Projectile Motion

  1. Jan 20, 2004 #1
    What do you do to find the x and y coordinates of a ball that is thrown from a building onto a slope?

    *Initial velocity is given along with the angle
    *The height of the building is given
    *And the angle of the sloped ground is given
  2. jcsd
  3. Jan 20, 2004 #2
    You should at least try and solve the problem since this place is for help not just asking physisists to solve the problems for you.

    Word of advice (sorry for offtop) read sticky notes

    No hard feelings
  4. Jan 20, 2004 #3
    Horizontal Component (a=0): v =vo + a*t; x =xo + vo*t +0.5*a*t^2; v^2=vo^2 + 2*a*(s-so)

    Vertical component (a=-9.81): v=vo + a*t; y=yo + vo*t + 0.5*a*t^2; v^2= vo^2 + 2*a*(y-yo)

  5. Jan 20, 2004 #4
    try using


    If your Vi is zero it can work out nicely if you find acceleration

    to find acceleration use

    Vf^2=Vi^2+2ad work it back assuming you know Vf, Vi and displacement
  6. Jan 20, 2004 #5
    I should have been more specific.

    Problem: The ball is thrown from the tower with a velocity of 20m/s. Determine the x and y coordinates to where the ball strikes the slope. Also, find the speed at which the ball hits the ground.

    **Picture attached

    Attached Files:

  7. Jan 20, 2004 #6
    The second part is really easy knowing your initial velocity and displacement you should be able to find your final velocity

    use Vf^2=Vi^2+2ad where a is acceleration due to earth's gravity and d is your displacement i.e. distance to the ground

    first part with the slope though I just simply don't understand -- picture would help a lot
  8. Jan 20, 2004 #7
    u need to know the slope
  9. Jan 21, 2004 #8
    The picture is in the post above.

    "Determine the x and y coordinates to where the ball strikes the slope."

    The ball doesn't land on a flat surface. The ground is raised by an angle of 26(degrees) to the horizontal.

    I hope that clears it up alittle better.
    Last edited: Jan 22, 2004
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook