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

Homework Help: Block on slope. mechanics.

  1. Nov 13, 2005 #1
    A wedge with mass M rests on a fricitonsless horizontal table top. a block with mass m is placed on the wedge. There is no friction between the block and the wedge. The system is released from rest.

    q1: calculate the accelration of the wedge

    now why would the wedge have any accelration at all? wouldn't just stand still?..

    I can't get how I'm suppose to calculate the acceleration of the wedge.
  2. jcsd
  3. Nov 13, 2005 #2
    The wedge exerts a reaction force on the thing on the wedge. From Newton's third law there must consequently be a force on the wedge equal to the normal reaction force. As this force is not perpendicular to the horizontal a component of this force is in the horizontal direction, producing an accelleration on the wedge.
  4. Nov 13, 2005 #3
    So if the normal force for the block is n the opposite one which is the one that acts on the wedge will be m*g*cos(aplha).. but how do I get the horizontel component for this force?
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook