GIVEN DATA
ENERGY THAT BATTERY CAN DELIVER IS E = 4.9
W·h
POWER P = 100W
TIMEÂ Â Â Â Â T = 11 h
WE KNOW THAT ENERGY = POWER*TIME
then ENERGY = 100*11 = 1100 Wh
A) FOR 4.9 W h cost is US$0.80
         1100 Wh
cost will be (1100/4.9)*0.80
                                    Â
= US$179.59
b) given that  US$0.06 per kilowatt-hour
    US$0.06 for on 1000 Wh
   for 1100 Wh the cost will
be  US$0.06 *1100/1000 Â
                                      Â
=Â Â US$0.066
