Question

An electric fan is turned off, and its angular velocity decreases uniformly from 460rev/min to 160rev/min in a time interval of length 3.60s .


Find the number of revolutions made by the motor in the time interval of length 3.60s .

Answer 1

\[\omega _{f}^{2} = \omega _{i}^{2} +2\alpha \theta \]
find alpha from
\[\omega _{f} = \omega _{i} + \alpha t\]
where omega final = 23/3 rev.s /sec
omega initial = 8/3 rev.s /sec
and t = 3.6 sec

Answer 2

sub.s alpha, omega final and omega initial in the top eqn. and solve for theta...

Answer 3

i got the 2 answers out of 3 :D thanks :D going to the next question :F