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: Free fall acceleration on a planet

  1. Mar 27, 2010 #1
    1. The problem statement, all variables and given/known data

    An astronaut on a strange planet finds that she can jump a maximum horizontal distance of 15 m if her initial speed is 3 m/s. What is the free fall acceleration on the planet?

    2. Relevant equations


    3. The attempt at a solution

    15=9sin2α/g g=9sin2α/15
  2. jcsd
  3. Mar 27, 2010 #2
    To have maximum range for a given initial velocity, her launch angle must be q0 = 45o. Her range then is R = (v02sin2q 0)/g' = v02sin90o/g' = v02/g'. We have g' = v02/R = 0.6m/s2.

    Source: http://electron9.phys.utk.edu/phys135d/modules/m3/Projectile%20motion.htm [Broken]

    Scroll down to almost at the bottom of the page.
    Last edited by a moderator: May 4, 2017
  4. Mar 27, 2010 #3
    Thanks for clarifying things up. I never knew that launching a projectile at 45 degrees would result in the greatest maximum range.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook