Answer:
[tex]\omega _{f}=15.51rad/sec[/tex]
Explanation:
We have have given that mass of the flywheel m = 35 kg
Diameter = 60 cm
Time t = 19 sec
Flywheel completes 90 complete revolutions
So [tex]\Theta =90\times 2\times \pi =565.2radian[/tex]
Initial angular speed [tex]\omega _{i}=420rpm =43.98rad/sec[/tex]
We know that angular displacement is given by
[tex]\Theta =\frac{\omega _{i}+\omega _{f}}{2}\times t[/tex]
[tex]565.2 =\frac{43.98+\omega _{f}}{2}\times 19[/tex]
[tex]\omega _{f}=15.51rad/sec[/tex]
