Answer
given,
height = 300 m
speed of aircraft = 40 m/s
propeller rotation = 20 rev/s
moment of inertia = I = 70 Kg/m²
mass = 200 Kg
since no non conservative force act on system, the mechanical energy is conserved after propeller fall off.
by conservation of energy
as there is no air resistance ωi = ωf
b) the rotation rate of the propeller remains same as there is no air resistance.
Yes. Even greater. Air resistance or drag becomes harder the faster an object goes. This is why when cars reach their max speed they don't accelerate as fast, because they are pushing harder against the wind. If I take a tennis ball and shoot it down a bottomless pit, a 400 kph, the drag will slow the ball down till it reaches terminal velocity.
-- high enough pressure
-- high enough temperature
-- presence of fusible material
Newton’s Second Law of Motion.