The flywheel of a steam engine runs with a constant angular velocity of 200 rev/
ID: 3901656 • Letter: T
Question
The flywheel of a steam engine runs with a constant angular velocity of 200 rev/min. When steam is shut off, the friction of the bearings and of the air stops the wheel in 2.7 h. (a) What is the constant angular acceleration, in revolutions per minute-squared, of the wheel during the slowdown? (b) How many revolutions does the wheel make before stopping? (c) At the instant the flywheel is turning at 100 rev/min, what is the tangential component of the linear acceleration of a flywheel particle that is 31 cm from the axis of rotation? (d) What is the magnitude of the net linear acceleration of the particle in (c)?
Explanation / Answer
Time required to stop = 2.7 hrs = 2.7 X 60 = 162 minutes
(a) Angular acceleration = 200 / 162 = -1.234 revolutions per minute-squared
v2 = u2 + 2aS
S = 200 X 200 / ( 2 X 1.234) = 16207.46 revolutions