4.5

4.5 describe a variety of everyday and scientific devices and situations, explaining the fate of the input energy in terms of the above relationship, including their representation by Sankey diagrams

 

 

1) Energy Value:

Wasted:             2*200=400J                                                                                                                                 

Heat-->Water: 5*200  1000J                                 

Sound E:            3*200=600J                                        

Check:           (400+600+1000=2000J)     

2)  Kettles efficiency: (Useful E/Total E )*100    

-->(1000/2000)*100à50%

3)  Energy converted into useful energy: Total E-Wasted E 

=150-(20+10)-->  150-30 --> 120J                                

4) Computer efficiency: (Useful E/Total E)*100-->(120/150)*100=0.8*100=80%