1. Limited time only! Sign up for a free 30min personal 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!

Homework Help: Nonuniform circular motion merry-go-round

  1. Oct 27, 2007 #1
    1. The problem statement, all variables and given/known data
    A 5.0-m-diameter merry-go-round is initially turning with a 4.0 s period. It slows down and stops in 20 s.
    a. Before slowing, what is the speed of a child on the rim?
    b. How many revoluotions does the merry-go-round make as it stops?
    ( Can i know what is a merry-go-round)


    2. Relevant equations



    3. The attempt at a solution

    I solved a) like that:

    V= 2(Pi)r/T
    V= 2(pi)(2.5)/4
    V= 3.93 m/s

    b) I think this is the correct equation:
    ([tex]\theta[/tex])f = [tex]\theta[/tex]o + [tex]\omega[/tex]o t + a/2r ( t^2)

    but i can't find [tex]\omega[/tex]o or a
     
  2. jcsd
  3. Oct 27, 2007 #2
    http://www.worldsfinestshows.com/equipment/images/MerryGoRound_1.jpg [Broken]
     
    Last edited by a moderator: May 3, 2017
  4. Oct 27, 2007 #3
    initially turning with a 4.0 s period ---> T
    ω=2pi/T
    α = △ω/△T

    θf = θo + ωo t + α/2( t^2)
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook