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 - have i done this correctly?

  1. Sep 8, 2008 #1
    I'm unsure whether I have done the following problem correctly :)

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

    A ball is kicked at from the slope as shown.
    When will the ball hit the slope?

    http://img90.imageshack.us/img90/8084/slopevi0.th.jpg [Broken]

    2. Relevant equations

    The distance travelled can be expressed in two components:

    The displacement compontents can also be expressed in terms of tan(a)

    3. The attempt at a solution

    Substituting we get:

    Is this correct?
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Sep 8, 2008 #2


    User Avatar
    Homework Helper

    Your approach is looks sound to me. The idea is you want to find the components x and y that match the slope of the ramp.
  4. Sep 8, 2008 #3


    User Avatar
    Homework Helper

    That looks fine.

    What you apparently developed is the equation for angle of the ball, as a function of t, from some point down the slope, and by setting the angle of tan to θ, that's where it hits and you have the value for the time now as a function of Vo and θ. Good job.
    Last edited: Sep 8, 2008
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook