Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Simple harmonic motion and maximum speed

  1. Mar 20, 2006 #1
    I got a question, what is the maximum speed of an object undergoing SHM? and what is the max. acceleration.

    I am not sure how to solve this without any data given. I know that velocity v=-Awsinwt. and accleration is a=Awcoswt.
    So how am I to find the max speed and max acceleration?. Pls help.
  2. jcsd
  3. Mar 20, 2006 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    The max acceleration is [itex] - A \omega^2 cos (\omega t) [/itex].

    Well, what is the max acceleration you could get if you can use any time you want? That will be when the cos is equal to minus 1!! (the max and min values of a cosine function are +1 or -1. Because of the overall minus sign, the acceleration will be maximum when the cosine function is minimum...which is when it is -1). When the sine is -1, what is the value of the acceleration? That's your answer.

    The velocity will be max when the sine function is minimum...
  4. Mar 21, 2006 #3


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    Alternatively, to find the maximum speed, you can use conservation of energy.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook