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Homework Help: Finding the number of revolutions for an car in an angular system

  1. Nov 2, 2008 #1
    1. The problem statement, all variables and given/known data

    The angular speed of an automobile engine is increased at a constant rate from 1500 rev/min to 3900 rev/min in 14 s.
    (A) What is its angular acceleration in revolutions per minute-squared?

    (B) How many revolutions does the engine make during this 14 s interval?

    2. Relevant equations
    I found out (A) to be 10285.71429 rev/min^2, but I have no idea how to do (B). would have to find tangential velocity or do i have enough information already?

    3. The attempt at a solution
    for (A), i used the formula [tex]\alpha[/tex] = [tex]\Delta[/tex][tex]\omega[/tex] / time
    so (3900rev/min - 1500rev/min)/14,
    and this was 10285.71420rev/min^2
    i just don't know how to start (B)..
  2. jcsd
  3. Nov 2, 2008 #2
    oh sorry, the alpha stands for angular acceleration
    the delta of little omega stands for change in anuglar speed :]
  4. Nov 2, 2008 #3
    whoops, change in angular* speed
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