1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Period of a Mass on a Spring in Simple Harmonic Motion

  1. Mar 22, 2007 #1
    Multiple force constants/Single mass?: SHM, Spring w/ mass.

    1. The problem statement, all variables and given/known data
    Kim drives her empty dump truck over a berm (also called a speed bump) at the contruction site. The truck has a mass of 3000kg and the force constant for one of the truck's springs is 100,000N/m (Remember, truck has 4 wheels).

    a)What is the resulting period of the bouncing truck as it goes over the bump?
    b)If Kim leaves the contruction site with a load of dirt in her truck, what will this do to the period of her dump truck as truck crosses berm?


    2. Relevant equations
    [​IMG]


    3. The attempt at a solution

    For part B, evaluating the equation and plugging in random numbers.. I'm pretty sure that more mass would result in a longer period..

    For part A, what's getting me is the (Remember, truck has 4 wheels) part.

    I can do T=2pi[square root (3000kg/(100000N/m)] which comes out to be 1.1s.. Or I don't know if I should multiply or divide or keep the 100000N/m by 4.. I think I've done as much work as I can without going in circles.. Would anyone like to tell me what I should do with the force constant (100000N/m)?
     
    Last edited: Mar 22, 2007
  2. jcsd
  3. Mar 22, 2007 #2
    a) I would just consider the four springs as one big spring with 4 times the spring force constant of one of them.
    b) What happens to the mass of the truck if it is loaded with dirt? How does T vary with m in the equation for the period?
     
  4. Mar 22, 2007 #3
    More dirt, more mass.. 50/2 is more than 12/2.. square root of 50/12 is more than 12/2 so yeah I'm pretty sure the period is going to be longer. PS, I'm plugging in random numbers for 50 and 12.
    ===
    Would like more responses.
     
    Last edited: Mar 22, 2007
  5. Mar 23, 2007 #4
    hello..
    PS, save mankind. Distribute your computing power:D
     
  6. Mar 23, 2007 #5

    Mentz114

    User Avatar
    Gold Member

    PugFug, you don't need to plug numbers in to see how mass affects the period. It's in the equation. If m gets bigger then so does T because they're both in the denominator. If k gets bigger T gets smaller because k is in the numerator - in other words you're dividing by k.
     
  7. Mar 23, 2007 #6
    I know part b already.. Just wondering about part a..
     
  8. Mar 24, 2007 #7

    Mentz114

    User Avatar
    Gold Member

    Just put the numbers you were given into the formula and calculate.
     
  9. Mar 24, 2007 #8
    Did you take into consideration the 4 wheels, one wheel has force constant of 100,000N/m? That could mean a total of 400,000N/m or the stress being reduced across all 4 to 25,000 or the load being the same on all..
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Period of a Mass on a Spring in Simple Harmonic Motion
Loading...