A fan is rotating with angular velocity `100 rev s^-1`. Then is switched off. It takes `5 min`to stop. (a) Find the total number of revolution made before the fan stops. (assume uniform angular retardation). (b) Find the value of angular retardation. ( c) Find the average angular velocity during this interval.

A fan is rotating with angular velocity `100 rev s^-1`. Then is switch

1.	A fan is rotating with angular velocity `100 rev s^-1`. Then is switched off. It takes `5 min`to stop. (a) Find the total number of revolution made before the fan stops. (assume uniform angular retardation). (b) Find the value of angular retardation. ( c) Find the average angular velocity during this interval.
Answer» (a) `theta = ((omega + omega_0)/(2)) t = ((100 + 0)/(2)) xx 5 xx 60 = 15000 rev`. (b) `omega = omega_0 + prop t` `rArr 0 = 100 - prop (5 xx 60) rArr prop = (1)/(3) rev s^-2` ( c) `omega_(a v) = ("Total angle of rotation")/("Total time taken")` =`(15000)/(50 xx 60) = 50 rev s^-1`.

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