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: Romeo throwing pebbles @window

  1. Sep 21, 2004 #1
    Ok...here's another problem that i keep getting wrong:

    *Romeo is chucking pebbles as gently as he can up to Juliet's window. That is, he wants the pebbles to hit the window with the least possible speed....He is standing at the edge of a rose garden at H = 7.70m below her window and at D = 8.90m from the base of the wall. How fast are the pebbles going when they hit her window?*

    Ok, so the horizontal component is 8.9m and the vertical is 7.7m...I tried
    - tan= 7.7/8.9 to get theta and then use that to get the hypoteneuse, but i realized, after getting the problem wrong, that I only got the distance of the hypoteneuse, when i really needed the velocity...so how would i find that? thx for any help
  2. jcsd
  3. Sep 21, 2004 #2
    Also remember that the pebbles would follow a projectile (parabolic) path, not a triangular path, due to the effect of gravity. Ignoring air friction (which is not present in this problem), the horizontal velocity of the pebbles will stay constant throughout their trajectory. Where in a parabolic path will the vertical velocity of the pebbles be the least?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook