1. Not finding help here? Sign up for a free 30min 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!

Newtons laws

  1. Sep 23, 2014 #1
    • Warning! Posting template must be used for homework questions.
    Three identical bricks are pushed across a table at constant speed as shown. Rank the magnitudes of all the horizontal forces that you identified in your free body diagram. So I identified the horizontal forces of push, friction, system a on system b, and b on a. I understand the force will equal 0 because they are moving at a constant speed and are equal and opposite. I am having trouble conceptualizing how if the force of the push is equal to the force of friction the blocks could possibly keep moving forever. If the force of the push equals the force of friction doesn't that mean it would stop moving because of friction??
     

    Attached Files:

  2. jcsd
  3. Sep 23, 2014 #2

    Orodruin

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    No, it means that there is a push force balancing the friction so that the object does not accelerate. In order to decelerate (slow down) an object there needs to be a net force on it according to Newton's second law and the friction would have to be larger than the push.
     
  4. Sep 23, 2014 #3
    Oooooh that makes a lot of sense. Thanks a lot!
     
  5. Sep 23, 2014 #4
    The answes lies in Newton's first law.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Newtons laws
  1. Newton's laws (Replies: 3)

  2. Newton's law (Replies: 8)

  3. Newton's laws (Replies: 5)

  4. Newton's Law (Replies: 2)

  5. Newtons law (Replies: 5)

Loading...