Example 1: A fan is rotating at 90 rpm. It is then switched OFF. It stops after 21
revolutions. Calculate the time taken by it
to stop assuming that the frictional torque
is constant.

luster is not a good characteristic to use by itself because luster is the property of minerals that indicates how much the surface of a mineral reflects light. the luster of a mineral is affected by the brilliance of the light used to observe the mineral surface.

use photo math tells u all the answers thats what i use