An engine flywheel initially rotates counterclockwise at 5.85 rotations/s. Then, during 21.3 s, its rotation rate changes to 3.31 rotations/s clockwise. Find the flywheel's average angular acceleration (including its sign) in radians per second squared. Define counterclockwise rotation as positive.

Question

Physics

Miguel Dillon

28 August, 06:55

An engine flywheel initially rotates counterclockwise at 5.85 rotations/s. Then, during 21.3 s, its rotation rate changes to 3.31 rotations/s clockwise. Find the flywheel's average angular acceleration (including its sign) in radians per second squared. Define counterclockwise rotation as positive.

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Answers (1)

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Jan Padilla · Answer 1

- 2.7 rad/s^2

Explanation:

f0 = + 5.85 rotations per second (counter clockwise)

t = 21.3 s

f = - 3.31 rotations per second (clockwise)

w0 = 2 x 3.14 x 5.85 = + 36.738 rad/s

w = - 2 x 3.14 x 3.31 = - 20.79 rad/s

Let α be teh angular acceleration.

α = (w - w0) / t

α = (-20.79 - 36.738) / 21.3

α = - 2.7 rad/s^2