Results 1 to 6 of 6

Math Help - Resolving normal components with 2 slopes

  1. #1
    Junior Member
    Joined
    Feb 2011
    Posts
    55

    Resolving normal components with 2 slopes

    The diagram (attached) shows a small ball of mass 2 kg, resting in the horizontal groove between two smooth planes inclined 20 degrees and 40 degrees to the horizontal. Find the magnitudes of the contact forces P and Q.

    I know I have to resolve the forces in one direction but I'm stuck cause I don't have any angles.

    Since it's in equilibrium the sum of all the forces in each direction is equal.
    Help appreciated.
    Attached Files Attached Files
    Follow Math Help Forum on Facebook and Google+

  2. #2
    MHF Contributor
    Joined
    Nov 2008
    From
    France
    Posts
    1,458
    Hi

    Do not forget the weight of the ball
    The equilibrium is given by \vec{P} + \vec{Q} + m\vec{g} = \vec{0}
    You can do the projection of this vectorial equality on any axis, for instance on each plane
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Junior Member
    Joined
    Feb 2011
    Posts
    55
    I don't know how to resolve these forces in any particular direction due to the different angles.
    Follow Math Help Forum on Facebook and Google+

  4. #4
    MHF Contributor
    Joined
    Nov 2008
    From
    France
    Posts
    1,458
    Look at the sketch below



    Axis xx' is parallel to the plane on the left
    We choose to project the vectorial relation on xx' (oriented upwards)
    What is the angle between P and xx', between Q and xx', between mg and xx' ?
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Junior Member
    Joined
    Feb 2011
    Posts
    55
    I have the angle between P and xx' as 30 degrees
    Q xx' 90 degrees
    and mg and xx' as 70 degrees

    Correct?
    Follow Math Help Forum on Facebook and Google+

  6. #6
    MHF Contributor
    Joined
    Nov 2008
    From
    France
    Posts
    1,458
    Yes correct
    Now you are able to do the projection of the vectorial relation on xx'
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. resolving for x
    Posted in the Pre-Calculus Forum
    Replies: 1
    Last Post: February 17th 2010, 05:54 PM
  2. Resolving forces on slopes
    Posted in the Geometry Forum
    Replies: 2
    Last Post: January 22nd 2010, 05:55 AM
  3. Resolving Vector Components
    Posted in the Math Topics Forum
    Replies: 19
    Last Post: October 19th 2009, 09:40 AM
  4. Replies: 1
    Last Post: May 23rd 2008, 04:44 AM
  5. Tangential and normal components
    Posted in the Calculus Forum
    Replies: 3
    Last Post: May 22nd 2008, 06:16 PM

Search Tags


/mathhelpforum @mathhelpforum