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Homework Help: Shock absorber thermodynamics

  1. Mar 2, 2014 #1
    1. The problem statement, all variables and given/known data

    How much energy must the shock absorbers of a 1240 kg car dissipate in order to damp a bounce that initially has a velocity of 0.840 m/s at the equilibrium position? Assume the car returns to its original vertical position.

    2. Relevant equations

    Fs = -kx

    The spring equation is he only thing that comes even close to making sense.

    3. The attempt at a solution

    I honestly don't know how to even get started, do I use the spring equation or something else. We covered thermodynamics and waves recently so it has to be from there, I just can't find any equation that would work.

  2. jcsd
  3. Mar 2, 2014 #2


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    Science Advisor
    Gold Member

    A shock absorber is more than just a spring. If it was just a perfect spring then it would not be very useful as you would just keep bouncing around. A shock absorber is basically a damped spring, it is a spring that is lossy in such a way that converts kinetic energy into thermal energy.

    So in this case, we have a car that has started to bounce with a given mass and velocity. How much energy will you need to dissipate to stop it's vertical movement?
  4. Mar 3, 2014 #3
    Kinetic energy, of course! Thank you.
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