The frequency of rotation of fan change from 2rev/s to 7rev/s in 10sec.find the angular acceleration.

Answer 1

V = Vo + a*t = 7.
2 + a*10 = 7,
a = 0.5 rev/s^2.

or a = 0.5rev/s^2 * 6.28rad/rev = 3.14 rad/s^2.