M= ?
g=9.8 m/s (2)
h=20 m 
Eg=362,600 J
Eg/mg
362,600 J/9.8 m/s (2) x 20 m 
=1,850 m
        
             
        
        
        
From what I know; When a sample of liquid water vaporizes into water vapor, the electrons in the water sped up due to heat. 
        
             
        
        
        
I think it’s 8 hours. I’m sorry if I’m wrong.
I just did 400 divided by 50
        
             
        
        
        
Answer:
M g H = 1/2 M v^2       potential energy = kinetic energy
v^2 = 2 g H = 2 * 9.80 * 6 = 117.6 m/s^2
v = 10.8 m/s     
 (C)