Answer:
ω = 0.05 rad/s
Step-by-step explanation:
In order to produce the acceleration equal to the acceleration due to gravity at the surface of Earth, the centripetal acceleration must be equal to the value of g:

where,
ω = angular speed = ?
g = acceleration due to gravity on the surface of the Earth = 9.81 m/s²
r = radius of cylinder = 8 km/2 = 4 km = 4000 m
Therefore,

ω = 0.05 rad/s