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!

Common forces in mechanics

  1. Jan 12, 2012 #1
    two blocks are connected by string if i pull a block,then block(it will transmit force) will also pull string then,string will also pull block (a& r pairs)forces on block are by me and by string of equal magnitude than why is block accelerating
     
  2. jcsd
  3. Jan 12, 2012 #2
    The force from the string on the block is not necessarily equal to your force on the block.
     
  4. Jan 12, 2012 #3

    jedishrfu

    Staff: Mentor

    common layman's usage is:

    I apply a force on a block and it moves.

    but for physics you need to think this way:

    I apply a force (f=ma) on a block of mass m and it accelerates (no friction case).

    in the real world with friction:

    I apply a force (f=ma) on a block of mass m and it accelerates to some constant
    speed because the frictional force increases with increasing speed and opposes the
    force Im applying.
     
  5. Jan 12, 2012 #4



    i am not getting it
     
  6. Jan 12, 2012 #5
    why? it because,the block may not transferring all force i am applying.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook