Adisk of radius 12 cm, initially at rest, begins rotating about its axis
, begins rotating about its axis with a constant
angular acceleration of 3 rad s-2 in 5 s. determine
a) the angular velocity of the disk
b) the tangential and centripetal accelerations of a point on the perimeter of the disk
c) the number of revolutions were made by the disk in those 5 s
d) write the relation between radial acceleration and linear velocity

acceleration = (change in speed) / (time for the change)

change in speed = (20-120)= -100 m/s.

1.5 min = 90 sec

acceleration = -100/90 = -1.11 m/s^2.

we don't care about the 150kg or the 2,500 meters. they don't make any difference.

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when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.

where is the