In order to describe motion along a straight line, you must state the speed and direction of the motion. Those two quantities, together, comprise what's known as "velocity".
Answer:
1742.24106 revolutions per day
Explanation:
v = Velocity
d = Diameter = 1.1 km
r = Radius = 
g = Acceleration due to gravity = 9.81 m/s²
g = 0.9 g
The centrifugal force will balance the gravitational force


The rotation speed is 1742.24106 revolutions per day
It's moving, in a straight line and at a constant speed. It can't be accelerating.