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!

Doubt in mass suspended by spring

  1. Feb 4, 2014 #1
    Consider a mass M, suspended by a weightless spring (horizontally or vertically). If I apply a force on the mass M, it executes simple harmonic motion. My question is for small displacement (that is pushed or pulled) according to Hooke's law F=-kx, it is equal to force we applied right?
    F=Ma=-kx, Can i apply Newton's 3rd law here? if yes explain? (But According to Newton's third law, action and reaction happens in different bodies right?)
    Last edited: Feb 4, 2014
  2. jcsd
  3. Feb 4, 2014 #2
    What is equal to the force?

    Newton's 3rd law is applicable in every inertial frame.
    If you are speaking of the reaction acting on you after you apply the force on the block, then the force acting on you will be equal to that of kx provided you exert the force slowly, i.e, without generating a kinetic energy in the block.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook