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Homework Help: Springs - Hooke's Law

  1. Nov 29, 2003 #1
    How do i find the force constant of a spring with a Newton meter?
    Do i graph the force applied vs. distance of stretch? What is on the x-axis, what is on the y-axis?

    How do i find an equation for the amount of skretch needed for on spring on a projectile, with the horizontal distance, angle of the projectile, mass and force constant given?
  2. jcsd
  3. Nov 29, 2003 #2
    What kind of text book are you using in your school?
  4. Nov 29, 2003 #3


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    Science Advisor

    F = kd
    k = F/d
    Now that you know the formula, it's easy to figure it out. Plot force on the Y axis and displacement on the x axis. The slope of the graph will give you the k value.

    Your second question is difficult to understand. Can you reword it or say it differently?
  5. Nov 29, 2003 #4
    Nelson Physics 12
  6. Nov 29, 2003 #5
    Re: Re: Springs - Hooke's Law

    I'm launching a spring off the end of an angled launch pad (projectile) at angle Өtheta, i want to find how long i have to skretch the spring in order for the spring to go x metres in the horizontal distance.

    i think i use the equation ½mv²=½kx² to find the velocity. Then I use that velocity in the equation d=[v²sin2(theta)]/g, to find the horizontal distance. Does that sound right, or is there an easier equation?
    Last edited: Nov 29, 2003
  7. Nov 29, 2003 #6


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    Combine the equations to get the result

    Range = (kx2 sin 2θ)/mg

    I can't see it getting any easier.
  8. Nov 29, 2003 #7
    Checkout Sample Problem #4 on pg 209
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