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: Finding angular speed/accel from tangential speed

  1. Oct 7, 2007 #1
    1. The problem statement, all variables and given/known data

    Professional recording studios often use reel-to-reel tape decks. On such a tape deck, the tape is pulled past the playback head at a constant linear speed of 0.381 m/s. (a) Using the data in part a of the figure, find the angular speed of the take-up reel. (b) After 2.79 x 10^3 s, the take-up reel is almost full, as part b of the drawing indicates. Find the average angular acceleration of the reel with the appropriate sign, where a positive value means the reel is speeding up.

    2. Relevant equations

    Vtangential = r*omega (which here will be w)
    accelerationtangential = r*alpha (here,alp)

    3. The attempt at a solution
    .381 m/s = r * w rad/s

    In the diagram, r isn't given. Is there a way I can find it? It's constantly changing because of the tape's reeling effect, so I'm not sure how that would fit in.

    Attached Files:

    • a.gif
      File size:
      3.8 KB
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted