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Homework Help: Simple harmonic motion problem

  1. Mar 10, 2012 #1
    A mass between 2 springs moves with shm.
    it oscillates between 2 points 5cm apart and completes 40 oscillations in 1min
    whats its max speed?

    Please help i always get the wrong answer
    The answer is 0.44 but why?
     
  2. jcsd
  3. Mar 10, 2012 #2

    gneill

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    Staff: Mentor

    Show your solution attempt. We can't tell what's going wrong if we don't see what you're doing.
     
  4. Mar 10, 2012 #3
    2pi*40/60= 4/3 pi
    f= 4/3pi*1/2= 2/3
    vmax= 2pi*2/3*2.5*10^-2
    but the answer is wrong :(
     
  5. Mar 10, 2012 #4

    gneill

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    Staff: Mentor

    Actually, your answer is correct. Looks like the answer key is wrong :smile:

    You've correctly calculated the frequency of the oscillations:

    ## A = 5 cm/2 ##

    ## f = 40 cycles/min ##

    ##\omega = \frac{40 cycles}{min} \times \frac{1\;min}{60\;sec} \times \frac{2 \pi \; rad}{cycle} = \frac{4}{3}\pi \frac{rad}{sec}##

    ## v = A \omega = \frac{10 \pi}{3}\frac{cm}{sec} = 0.105 m/s ##
     
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