Answer:
15.66 rad/s
Explanation:
The vertical motion and horizontal motion are independent of each other.
t = √ ( 2 s/ g) where t = time for the ball to reach the ground and s is the height of the cliff = 18.0 m
t = √ ( 36 / 9.81 ) = 1.916 secs
horizontal distance travel = ut where u is the horizontal velocity of the stone = 30 × r (radius)
tangential velocity V = angular velocity ( ω) × radius
distance traveled = ω × r × t = 30 × r
radius cancelled on both side
ω = 30 / 1.9156 = 15.66 rad/s