Answer:
The driving force for (a) heat transfer is temperature difference. (b) electric current is voltage difference. (c) fluid flow is pressure or hydraulic head difference.
Explanation: (a) The driving force for heat transfer is temperature difference. Heat transfer between two mediums is possible only if the two mediums are at different temperature, the higher the temperature, the higher the heat transfer.
(b) The driving force for electric current is voltage difference. Voltage difference is defined as the potential difference in charge between two points in electrical field. For electric current to occur,the voltage must be high.
(c) The driving force for fluid flow is pressure difference or hydraulic head difference. For fluid to move upward,it requires energy. 
 
        
             
        
        
        
Compression and rarefaction are two phenomenon occurs in longitudunal wave!
when there is denser particle gathering in that wave , there we called it compression and the rarer part of particles is rarefaction !
        
                    
             
        
        
        
32 kg m/s would be the kinetic energy.
        
             
        
        
        
Answer:
 B
Explanation:
Sunlight comes in the form of light energy. Upon striking the solar panels, it converts the light energy into electrical energy so as to run throughout the circuits. Then since it's used to power light, the electrical energy will be converted back into light energy 
 
        
                    
             
        
        
        
Answer:
It is because it cannot be used time again and again.