Answer to Question #285505 in Mechanics | Relativity for Jay

Question

The fan blades are rotating with an angular speed of -120 rad/s . As the plane takes off, the angular velocity of the blades reaches -390 rad/s in a time of 19s. Find the angular acceleration, assuming it to be constant.

Answer 1

Answer

Initial angular speed

$\omega_0=-120rad/sec$

After t=19 sec angular speed

$\omega=-390 rad/sec$

Now newton equation of motion of circular motion

Then angular acceleration

$\alpha=\frac{\omega-\omega_0}{t}$

Putting all values

$\alpha=\frac{-390+120}{19}=14.21 rad/sec^2$