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Homework Help: Bowling ball force problem

  1. Sep 28, 2003 #1
    I am having difficulty solving this problem. I even asked my teacher for help but her equation did not work and I am confused even more. Can someone please help me?

    Q. When you lift a bowling ball with a force of 82 N, the ball accelerates upward with an acceleration a. If you lift with a force of 99 N, the ball's acceleration is 2*a.
    a) Find the weight of the bowling ball.
    b) Find the acceleration a.

    This is how I tried it but i dont know if this is correct:

    82N-w=m*a

    99-W=2ma
     
  2. jcsd
  3. Sep 28, 2003 #2

    Claude Bile

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    Your equations look correct, however they appear to overcomplicate the problem. The question basically states that 17 N provides an upward acceleration of m*a.

    Thus if 82 N provides an upward acceleration of m*a, (82-17)N must provide no acceleration - this is the weight of the ball.

    Now you know both m*a and m*g, two equations with two variables that are relatively easy to solve.

    Claude.
     
  4. Sep 28, 2003 #3

    krab

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    I find that to be a rather peculiar comment. Nerak, your equations are correct, AND they are the simplest description of the problem. Claude, the question does NOT "basically state that 17 N provides an upward acceleration of m*a". You got that be intuitively making exactly the subtraction suggested by Nerak's equations. Do not dissuade people from translating a probelm into equations. Intuition won't get you far in physics.
     
  5. Sep 29, 2003 #4

    Claude Bile

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    True, the question did not explicitly state that 17 N provides an upward acceleration of m*a, rather it is a logical derivation from the information provided in the question, there was no intuition involved.

    I did not intentionally attempt to dissuade Nerek from using his (correct) equations, I merely offered a worded interpretation of how to arrive at the answer (as Nerek was unsure of whether he was correct) that I thought may be helpful.

    Claude.
     
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