Answer:489 Revolutions
Explanation:
Given
Angular deceleration
Given wheel angular velocity =96 rad/s when machine is turned off
time taken by machine to reach zero angular velocity

0=96+(-1.5)t
t=64 sec
angular displacement is given by


For revolutions =
Answer:
as we move higher altitudes force of gravity us decreases
That depends on several things that we don't know.
A few of them are:
-- the size of the sample
-- what level of radioactivity was measured at the beginning
-- what's the unit of the 12.5
-- the half-life of the substance involved