Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

A very dumb question (about different masses and accelerations)

  1. Jun 19, 2012 #1
    Why do different masses released at the same time fall to the ground with the same acceleration. Isn't the universal law of gravitation F=G*M(e)*m/r^2? i.e. if masses are unequal the force on both the objects will be different and hence acceleration will be unequal...
  2. jcsd
  3. Jun 19, 2012 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2016 Award

    Re: A very dumb question...

    Please start by reading the FAQ subforum in the General Physics forum

  4. Jun 19, 2012 #3
    Re: A very dumb question...

    a=F/m .....(1)
    From your post,

    Subtitute in equation (1)

    a= F/m=(G*M(e)*m/(r^2m)= G*M(e)*/r^2
    You see m is missing in final equation.
    Acceleration due to gravity does not depend on the mass.
  5. Jun 19, 2012 #4


    User Avatar
    Science Advisor
    Homework Helper

    Re: A very dumb question...

    Increasing the mass does indeed increase the force but increasing the mass also reduces the acceleration (f=ma so a=f/m).

    Overall the mass cancels as per the answer by azizlwl.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook