Answer:
[tex]\alpha = -151 rad/s^2[/tex]
Explanation:
As we know that blades are moving at speed of 6200 rpm
so here we can say that
[tex]f = 6200 rpm = \frac{6200}{60} rev/s[/tex]
[tex]f = 103.33 rev/s[/tex]
now we know that angular speed is given as
[tex]\omega = 2\pi f[/tex]
[tex]\omega = 2\pi(103.33) = 649.3 rad/s[/tex]
now it comes to rest after t = 4.3 s
so angular acceleration is given as
[tex]\alpha = \frac{\omega_f - \omega_i}{\Delta t}[/tex]
[tex]\alpha = \frac{0 - 649.3}{4.3}[/tex]
[tex]\alpha = -151 rad/s^2[/tex]
