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Homework Help: Forces and angles question

  1. Feb 28, 2005 #1
    I'm having trouble with this question because of the angles. Could someone point me in the right direction.

    Two forces F1 and F2 act on a body of mass 28kg. F1 has a magnitude of 8N and is directed due east. The second force F2 has a magnitude of 10N and acts in a direction 50 degrees west of north. Find the magnitude and direction of the acceleration of the 28kg mass.
  2. jcsd
  3. Feb 28, 2005 #2
    Maybe you'll find it easier to think of F2 as being "40 degrees north of west" instead of "50 degrees west of north". Then, resolve F2 into a West component and a North component using sin 50 and cos 50. The question is, which is which?

    Draw a diagram & you should be able to figure that out.
  4. Mar 1, 2005 #3


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    You needn't change the angles...Simply choosing mutually perpendicular axis and ading the vectors in terms of components will do the job...

  5. Mar 2, 2005 #4
    vectors and angles...

    I think I understand how to figure out each component individually but am unsure how to put them together toget the magnitude and direction.
  6. Mar 2, 2005 #5


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    If you have the components,the u can make use of the right triangles and of Pythagora's theorem (for the absolute value/magnitude) and arctangent (for direction/angle)...

    It's not difficult.

  7. Mar 2, 2005 #6
    try doing it geometrically if you dont see it algebraically. Plot the vectors on a grid, head to tail, and then using the points coordinates, find the magnitude by using length of a line formula.


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