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Time required to move object

  1. Feb 22, 2007 #1
    1. The problem statement, all variables and given/known data

    What is the time required to move an object of .1kg a distance of .1m
    with a force of .0000000132944 N ?

    2. Relevant equations

    N = 1kg m/s^2

    3. The attempt at a solution

    N = 1kg m/s^2

    N = 1kg m/s^2

    S^2 = 1kg m/ N

    sqrt s^2 = sqrt 1kg m/ N

    S = sqrt 1kg m/ N

    S = sqrt .1 (.1)/0.000000000132944

    S = sqrt .01/0.000000000132944

    S = 877s
    Last edited: Feb 22, 2007
  2. jcsd
  3. Feb 22, 2007 #2


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    Homework Helper

    No, that is not correct. You have taken the units of a quantity and made an equation out of it. Are you trying to use Newton's second law? Write the actual equation out. What do you first need to find out about the object's motion if a force is acting on it?
  4. Feb 22, 2007 #3
    What I need to do is calculate the time required for an object with a set mass to move a set distance, with a set force exerted upon it.

    Newton's second law, F = ma, requires that I know a, acceleration, which is expressed in meters (or other measurement) per second squared. However, I do not know how many "second squared" it takes.

    In the contezt of the problem: A mass of 100g is placed on a beam free to rotate. Ten cm away, a larger mass is placed. The gravitational force between the two masses is 0.000000000132944 N, found through previous calculations. The distance is 10 cm (.1m), and the mass of the object is 100g (.1kg). How long does it take the object, with the force being applied to it, to come into contact with the attractive mass?
  5. Feb 22, 2007 #4


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    Homework Helper

    But I don't think you can take gravitational force as a constant force, because of the 1/d^2. So as the object gets closer it will accelerate faster. Is it assumed these objects are point masses? I'm guessing there might be information you haven't shared since there is no mention of the mass of the larger object in any of your previous posts (how else did you find F?).

    Perhaps I'm being too rigorous with this, or I'm not understanding something??

    "I do not know how many "second squared" it takes."

    I'm not sure what you're trying to do with that. Those are units, not variables in your equation. Use Newton's second law to find acceleration since you know the force acting on the object and the mass of the object. You express this acceleration in m/s^2. You can then go on to find the time by basic kinematics.
    This is of course assuming a constant force on the object.
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