A. when it reaches the top of its flight
potential energy increases as the height of the object does, and the highest point of a ball's flight is when it reaches the top. 
        
                    
             
        
        
        
Answer:
Vehicles typically employ both hydraulic shock absorbers and springs or torsion bars. In this combination, "shock absorber" refers specifically to the hydraulic piston that absorbs and dissipates vibration.
Explanation:
hope this helps 
 
        
             
        
        
        
If I remember correctly, it is the 3rd answer choice.
        
             
        
        
        
Answer: 0.25 m/s
Explanation:  Speed = wavelengt · frequency  
v = λf   and frequency is 1/period  f = 1/T
Then v = λ/T = 5 m / 20 s = 0.25 m/s