Answer:
76.0198 rev/sec
Explanation:
Given
Torque ( T ) = 29.1 N
Moment of inertia = 0.142 kg.m²
Ф = 14.1 rev
F =
F = T ΔФ
w² =( 2TΔФ)/I =
w = √5779.01 = 76.0198 rev/sec
e
fo = 378.52Hz
Using Doppler effect formula:
where
f' = 392 Hz
C = 340m/s
Vb = 20m/s
Va = 31m/s
Replacing these values and solving for fo:
SEE EXPLANATION