Explanation:
A wave having a frequency of 200 Hz means that 200 such waves pass through a point per second.
 
        
             
        
        
        
100kg x bicycle speed = 1400 X 2
bicycle speed = 2800/ 100
bicycle speed = 28 m/s
        
             
        
        
        
2NO2 means that there is 2 oxygen atoms and one nitrogen with two sets of that. So its the third one
        
                    
             
        
        
        
The reason why there is no energy shortage nor will there ever be is because energy is being preserved and conserved and only changes form. It never gets lost or increased.