Variable Steam
Posted in Uncategorized on 05/04/2010 12:53 am by adminVariable Steam
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 BLACK DECKER AS75 QUICK PRESS IRON WITH VARIABLE STEAM AND NONSTICK SOLEPLATE  US $29.36
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| computer help |
Relating the Translational and Rotational Variables of a steam engine...?
The flywheel of a steam engine runs with a constant rotational velocity of 150 rev/min. When steam is shut off, the friction of the bearings and of the air stops the wheel in 2.2 h.
(a) What is the constant rotational acceleration, in revolutions per minute-squared, of the wheel during the slowdown? (b) How many rotations does the wheel make during the slowdown?
(c) How many rotations does the wheel make before stopping?
(d) At the instant the flywheel is turning at 75 rev/min, what is the tangential component of the translational acceleration of a flywheel particle that is 50 cm from the axis of rotation? (e) What is the magnitude of the net translational acceleration of the particle in (d)?
Can you explain your answers, and show the equations you used to solve this?
Variables: 150 rev/min 2.2h = 140 min
(a) Difference in velocity (150 to 0) over difference in time (0 minutes to 140)
delta v / delta t (150-0)/(0-140) = -1.0714 rev/min/min
Acceleration is negative since it is slowing down.
(b) during the slowdown? one less than the answer to (c)?
(c) (v not times delta t) / acceleration absolute value (150*140)/|-1.0741| = 19553.07 revs
(d) and (e) email if you really want, but this stuff should give you a start. Hope this isn't due for a couple days tho.
