1. PF Contest - Win "Conquering the Physics GRE" book! Click Here to Enter
    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!

B Galileo's law of inertia

  1. Sep 29, 2016 #1
    How galileo proved his first law of motion ie law of inertia by taking conclusions from rolling ball experiments.
  2. jcsd
  3. Sep 29, 2016 #2
    Galileo showed that the prevailing idea of Aristotle about forces being necessary to keep objects in motion was not correct..

    Although a force is needed to start an object moving,Galileo showed that, once it is moving, no force is needed to keep it moving except for the force needed to overcome friction.
    When friction is absent, a moving object needs no force to keep it moving. It will remain in motion all by itself.

    Galileo tested his idea by conducting following experiments .

    He rolled balls down inclined planes and observed and recorded the gain in speed as rolling continued.
    On downward-sloping planes, the force of gravity increases a ball’s speed.

    On an upward slope, the force of gravity decreases a ball’s speed.

    He asked -What about a ball rolling on a level surface?

    While rolling on a level surface, the ball neither rolls with nor against the vertical force of gravity and it neither speeds up nor slows down. The rolling ball maintains a constant speed.
    Galileo reasoned that a ball moving horizontally would move forever, if friction were entirely absent .
    Such a ball would move all by itself of its own inertia.
  4. Sep 29, 2016 #3
    Thanks , your answer made be satisfied
  5. Sep 30, 2016 #4
    the customary thanks on this forum is just to 'like' a post.
  6. Sep 30, 2016 #5


    User Avatar

    Staff: Mentor

    Replying with a few words of appreciation is equally customary. :smile:
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted