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!

B Which of the two is the reason a block slides down a wedge?

Tags:
  1. May 1, 2016 #1
    FBu5G.png
    Is the reason the block slides down the plane that the resultant of the normal force N and mg acts along the plane causing it to slide or is it because of the component of mg parallel to the plane acting on the box i.e. mgsin(theta)
     
  2. jcsd
  3. May 1, 2016 #2

    jbriggs444

    User Avatar
    Science Advisor

    Both are the same thing.
     
  4. May 1, 2016 #3
    Wait, what? How?
     
  5. May 1, 2016 #4
    Isn't N cancelled out by mgcos(x)?
     
  6. May 1, 2016 #5

    jbriggs444

    User Avatar
    Science Advisor

    But both N and the component of gravity perpendicular to the slope are perpendicular to the slope.
     
  7. May 1, 2016 #6
    But in opposite directions, isn't it?

    Pardon me but my mechanics suck
     
  8. May 1, 2016 #7

    jbriggs444

    User Avatar
    Science Advisor

    Right. They are in opposite directions and are equal. They add to a net of zero. All that is left after you add normal force plus gravity is the component of gravity parallel to the slope.

    The resultant of normal force plus gravity is equal to mg sin theta.
     
  9. May 1, 2016 #8
    Oh, I see. Thanks!
     
  10. May 3, 2016 #9

    CWatters

    User Avatar
    Science Advisor
    Homework Helper

    Perhaps make your drawing like this...

    FBu5G.png
     
  11. May 3, 2016 #10

    David Lewis

    User Avatar
    Gold Member

    Just to clarify, you do not have 3 forces acting on the block.
    You can consider N + mg to be acting, or the resultant to be acting, but not both.
     
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: Which of the two is the reason a block slides down a wedge?
  1. Block on wedge (Replies: 1)

  2. Block on a wedge (Replies: 3)

Loading...