1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: A Cannon/Cliff Physics Question?

  1. Nov 6, 2012 #1
    1. The problem statement, all variables and given/known data
    A cannon is placed at the bottom of a cliff 85 m high. If the cannon is fired straight upward, the cannonball just the reaches the top of the cliff.
    a) Calculate the initial speed of the cannonball.
    b) Suppose a second cannon is placed at the top of the cliff and fired horizontally with the same initial speed as part (a). Prove numerically that the range of this cannon is the same as the maximum range of the cannon from the base of the cliff.

    2. Relevant equations
    for a) v^2 = 2gh
    for b) ymax = (v^2 sin^2 ∅)/2g

    3. The attempt at a solution

    for a) i got v = 40.8375 m/s

    for b) i got ymax = 85 meters but that is only for the vertical part.

    I am not sure how to find the numerically part
  2. jcsd
  3. Nov 6, 2012 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Not a useful equation for this question. Do you have any equations relating to range?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook