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: Diving off a cliff

  1. Sep 15, 2010 #1
    1. The problem statement, all variables and given/known data
    A diver running 2.2 m/s dives out horizontally from the edge of a vertical cliff and 2.5 s later reaches the water below. How high was the cliff?

    2. Relevant equations

    I have Y as being 0 (the point when they hit the water) and velocity of y at time zero being 2.2 m/s.

    3. The attempt at a solution
    I used the equation above and substituted and got 0=y+(2.2)(2.5)-.5(9.8)(2.5^2) and got 25 for y, but my online homework says it's wrong. I've double checked and can't figure out where I went wrong.
  2. jcsd
  3. Sep 15, 2010 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    The diver has an initial speed of 2.2m/s in the horizontal direction. What is the diver's initial speed in the vertical direction?
  4. Sep 15, 2010 #3
    zero, because they are not moving either up or down yet, thank you very much!
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook