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Homework Help: Help with Tension Problems

  1. Oct 11, 2005 #1
    Hi! The following 2 questions I have for homework for this week, and I'm stuck on the steps I need to approach this types of questions.
    If someone could provide a brief analysis or suggestions as to how to go about problems involving tensions, that would be very helpful.

    1) If M=1.1kg, what is the tension in the string 1?

    2) Two objects are connected by a light string that passes over a frictionless pulley. Draw a Free Body Diagram of both objects. If the inclide is frictionless and if m1= 2kg, m2=6kg and angle theta=55 degrees, find:
    (a) the accelerations of the objects
    (b) the tension in the string
    (c) the speed of each object 2 sec after being released from rest.

    ANY feedback about analysing tension questions such as the ones mentioned above would terrific. Physics is really not my strong point. In a free body diagram in #2, what forces are acting on the objects being pullied? Gravity? Normal?

    Attached Files:

  2. jcsd
  3. Oct 11, 2005 #2

    Tom Mattson

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    Staff Emeritus
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    Gold Member

    You would follow the same procedure for both of them.

    * Identify the forces acting on the object in question.
    * Draw a free body diagram showing only the forces (no cables or inclined planes or anything else)
    * Sum the forces and apply Newton's second law: [itex]\Sigma\vec{F}=m\vec{a}[/itex]

    I wouldn't call that a free body diagram, because it shows the physical apparatus and not the force vectors.

    Yes, both of those are acting, but that's not all. There's also a rope attached to that object, and a force is transmitted through it.
  4. Oct 13, 2005 #3
    tension in first string is MG = 1.1x9.8=10.78N
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