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!

Shm help

  1. Dec 6, 2006 #1
    1. The problem statement, all variables and given/known data

    Astronauts in space cannot weigh themselves by standing on a bathroom scale. Instead, they determine their mass by oscillating on a large spring. Suppose an astronaut attaches one end of a large spring to her belt and the other end to a hook on the wall of the space capsule. A fellow astronaut then pulls her away from the wall and releases her. The spring's length as a function of time is shown in the figure.
    http://session.masteringphysics.com/problemAsset/1001073/9/knight_Figure_14_36.jpg

    What is her speed when the spring's length is 1.2 ?


    2. Relevant equations



    3. The attempt at a solution

    i tried to write the position as x(t)= .6+1.4sin((2pi/T)t)
     
  2. jcsd
  3. Dec 6, 2006 #2

    berkeman

    User Avatar

    Staff: Mentor

    The center of the sine wave is at 1.0m, not at 0.6m

    Re-write the position equation with a number for T, then differentiate and figure out what phase to plug into the velocity equation. You're good to go!
     
  4. Dec 6, 2006 #3

    nrqed

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Yes...Keep going. To find the speed you have to differentiate your equation, find the time corresponding to a position of 1.2 , plug that time in your equation for the velocity and get your answer. (you may read the period T from your figure)

    Patrick

    EDIT: I just noticed on the figure that the oscillation is from 0.6 to 1.4, so the equation should be [itex] 1+ 0.4 sin ({2 \pi \over T} t ) [/itex]
     
    Last edited: Dec 6, 2006
  5. Dec 6, 2006 #4
    so i should differentiate [itex] 1+ 0.4 sin ({2 \pi \over T} t ) [/itex]
    for t and Tshould be 3??
     
  6. Dec 7, 2006 #5

    berkeman

    User Avatar

    Staff: Mentor

    Yep, that's the next step.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Shm help
  1. Shm physics help (Replies: 2)

  2. Waves & SHM, HELP (Replies: 2)

  3. Help with SHM (Replies: 0)

  4. SHM Help (Replies: 7)

Loading...