Answer:
 The angular velocity is 
5.64rad/s
Explanation:
This problem bothers on curvilinear motion 
The angular velocity is defined as the rate of change of angular displacement it is expressed in rad/s
We know that the velocity v is given as
v= ωr
Where ω is the angular velocity
 r is 300mm to meter = 0.3m
 the radius of the circle 
 described by the level 
 v=1.64m/s
Making ω subject of the formula and solving we have
ω=v/r
ω=1.64/0.3
ω=5.46 rad/s
 
        
             
        
        
        
Question 18: a
question 19: b
question 20: c
        
                    
             
        
        
        
Since the tower base is square with a side length of  125 m,
Therefore,

Square root of 31250 = 176.776953 (Diameter)
, so this is the diameter of the cylinder to enclose it, and radius, r = 88.38834765 m and height, h = 324 m.
The volume of cylinder,

Thus, the mass of the air in the cylinder,

Hence, the mass of the air in the cylinder is this more  than the mass of the tower.
 
        
             
        
        
        
-- Well first of all, the waves are <em>transverse waves</em>.  The fibers in the rope, and the hand that generates the waves, are moving up and down, but the wave is moving to the right, towards the wall.  These directions are perpendicular.
-- Later on, after the waves reflect from the wall and travel back toward the hand, there are going to be <em>standing waves</em> on the rope.  But this is probably beyond the scope of the question.