An electric fan is turned off, and its angular velocitydecreases uniformly from 460 rev/min to 210 rev/min in a timeinterval of length 4.15 s . a)Find the angular acceleration inrev/s2. b)Find the number of revolutions made by the motor in thetime interval of length 4.15 s . c)How many more seconds arerequired for the fan to come to rest if the angular accelerationremains constant at the value calculated in part A?
An airplane propeller is 1.83 m in length (from tip to tip) withmass 128 kg and is rotating at 2800 rpm (rev/min) about an axisthrough its center. You can model the propeller as a slenderrod.
a)What is its rotational kinetic energy?
b)Suppose that, due to weight constraints, you had to reduce thepropeller's mass to 75.0% of its original mass, but you stillneeded to keep the same size and kinetic energy. What would itsangular speed have to be, in rpm?
