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Homework Help: Calculate the magnitude and direction of the resultant force on the object.

  1. May 9, 2010 #1
    I have the following question.
    How do I work this out:

    There is an object 9N<-----------[OBJECT]--->3N--->4N...............[The ---> represent the direction in which the object is being pulled, and the 3N and 4N pull into the same direction.
    Now its asking me:
    1. Calculate the magnitude and direction of the resultant force on the object.
    2. Calculate the magnitude of the acceleration of the object.

    Could someone please help me find the answer?
    And if anyone knows the answer could they please explain how they got it?
    Thank you.
    Last edited: May 9, 2010
  2. jcsd
  3. May 9, 2010 #2
    state the problem in exact language.
  4. May 9, 2010 #3
    What do you mean?
    Thats exactly what it says on my paper..
  5. May 9, 2010 #4
    For part A, just call <----- negative and ------> positive. -9 N + 7 N = -2 N.

    I don't think part B is solvable without knowing the mass of the object.
  6. May 9, 2010 #5
    It says it has a mass of 0.5KG.
    So for part A the answer for magnitude would be -2 and the direction would be "left"?
  7. May 9, 2010 #6
    Almost. The magnitude is 2 and the direction is left. If the magnitude were -2 and the direction was to the left left, the motion would actually be to the right. That may be a bit confusing- does it make sense to you?

    Now that you know the mass, you can use F=ma to find the magnitude of the acceleration.
  8. May 9, 2010 #7
    Hey yeah good sense.
    Two negatives make a positive kinda thing.
    ok So F=ma perfect thanks!!
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