Question

An electric fan has a low speed of 3.00 rotations per second and a medium speed of 9.00 rotations per second. The fan rotates counter-clockwise, CCW. a) The fan is running on low speed when it is switched to medium speed. It takes 4.00 seconds for the fan to reach medium speed. What is the angular acceleration, LaTeX: \alphaα? b) If the rotational inertia of the fan is Ifan = 1.50 x 10-3 kg-m2, calculate the Net torque, LaTeX: \tau_{net}τ n e t, required for part a.

Answer 1

Answer:

α=9.42 rad/s    T= 0.014 rad/s$^{2}$

Explanation:

Low speed= Wi=3 rps = 3*2*π rad/s= 6π rad/sec

Medium speed= Wf= 9 rps= 9*2*π rad/sec= 18 rad/sec

time= t= 4 sec

Angular acceleration=α=$\frac{Wf-Wi}{t}$

⇒α=(18 π - 6 π)/4

⇒α=9.42 rad/s

b).

Rotational inertia= I = 1.5*10^-3 kg-m^2

Net torque= T = I*α = (1.5*10^-3) * (9.42) rad/s^2

⇒T= 0.014 rad/s^2