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!

Find the magnitude of the velocity vector on impact

  1. Nov 4, 2008 #1
    (resolved) find the magnitude of the velocity vector on impact

    Thelma and Louise drive their '66 T-Bird convertible off a cliff. They are going 25.9 m/s and the cliff is 97 meters high. Find the magnitude of their velocity vector the moment they impact the ground. Make sure you do the following in your answer:

    DO NOT include units. We'll deal with that in the next question.
    Give precision to tenths (#.#).
    Make your answer correct to within 0.2

    so given y is -97, and vi is 25.9 m/s


    equations for horizontal projectile motion for vf are
    vyf=-g(t)
    vf=sqrt of (vxf^2+vyf^2)
    so far for t i had 4.447seconds

    ____
    \/-2*-97
    ----------= 4.447
    9.81
    and had vyf as -44.6m/s
     
    Last edited: Nov 5, 2008
  2. jcsd
  3. Nov 4, 2008 #2

    mgb_phys

    User Avatar
    Science Advisor
    Homework Helper

    You don't need the time.
    You can use vf2 = vi2 + 2as for the vertical velocity
    Since you ignore air resistance there is no change in the horizontal velocity.
     
  4. Nov 4, 2008 #3
    And think of vxf and vyf as being two legs of a right triangle. The answer you're looking for is the hypotenuse of this triangle.
     
  5. Nov 4, 2008 #4
    what is 2as????
     
  6. Nov 4, 2008 #5

    mgb_phys

    User Avatar
    Science Advisor
    Homework Helper

    2 * acceleration * distance
    It's one of the standard motion equations - although some books use different letters.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Find the magnitude of the velocity vector on impact
Loading...