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Homework Help: Vector problems

  1. Sep 19, 2009 #1
    1. The problem statement, all variables and given/known data
    Could anyone help me with these vector problems?

    1. At the top of its flight, an arrow has a horizontal velocity of 35ms-1. Two seconds later its velocity is 40ms-1 at an angle of 29 degrees below the horizontal. After a further 2 seconds, it is moving at 53ms-1 at 49 degrees below the horizontal. What has happened to the horizontal velocity component during these 4 seconds? Use the vertical velcotiy components to find a value for the arrow's uniform vertical acceleraton. Comment on your value

    2. A young child is enjoying a swing. When the swing stops, mum pulls it back wth a horizontal force through an angle of 25 degrees. In this position, the tension in the chain is 110N. Use the horizontal and vertical components of the tension in the chain to find the two other forces acting on the swing when it is at rest in this position

    2. Relevant equations

    3. The attempt at a solution
    1. well for at the moment ive got 2 triangles? one with an angle of 29 and one with an angle of 49 with the adjacent at 35 im just not sure what to do their to go onto the trigonometry

    2. i have no clue on how to start this question
  2. jcsd
  3. Sep 19, 2009 #2


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    Staff Emeritus
    Science Advisor
    Homework Helper

    1. You'll need to use some trig (sin and cos) to get the horizontal and vertical components of each velocity.

    2. Draw a free body diagram for the swing, showing all forces acting on it. They tell you what the tension force (both magnitude and direction) is.

    p.s. welcome to Physics Forums!
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