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: Angular acceleration of machinery

  1. Jul 23, 2008 #1
    A piece of machinery is spinning at 760rpm . When a brake is applied, its rotation rate drops to 480rpm while it turns through 210 revolutions.

    What is the magnitude of the angular deceleration?

    Answer in Rad/s^2

    Eqn I used:[tex]\omega[/tex]^2=[tex]\omega[/tex]_0_^2+2[tex]\alpha[/tex](change in theta)

    I put 480^2=760^2+2(alpha)210

    I got 3.79e-3...
    what did I do wrong? Ithink its the units, they are very confusing.
  2. jcsd
  3. Jul 23, 2008 #2
    i'd convert the distance to radians, and all the speeds to radians per sec right off the bat. so 760 rpm x 2pi / 60 would give you rad/s for example
  4. Jul 23, 2008 #3
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook