I don't know what I'm doing wrong. I would really appreciate some help :)
12.
A particular type of automobile storage battery is characterized as “493 - Ampere - hour, 16.8 V.”
What total energy can the battery deliver?
Answer in units of J
13. A 102.2 W, 158.3 V light bulb is plugged into
a 72.2 V outlet.
If energy costs 9.1 cents/kW· h, how much
does it cost per month (30 days) to leave the
light bulb turned on?
Answer in units of cents
12.
A particular type of automobile storage battery is characterized as “493 - Ampere - hour, 16.8 V.”
What total energy can the battery deliver?
Answer in units of J
13. A 102.2 W, 158.3 V light bulb is plugged into
a 72.2 V outlet.
If energy costs 9.1 cents/kW· h, how much
does it cost per month (30 days) to leave the
light bulb turned on?
Answer in units of cents
-
12. 493A-hr*16.8V = 8,282.4W-hr*3600s/hr = 29.817MJ
13. Assume the values given are RMS:
Power = V^2/Rb = 102.2W
=> Rb = 158.3^2/102.2 = 245.2 Ohms where Rb is the resistance of the light bulb.
Power = V^2/Rb = 72.2^2/Rb = 21.26W
=> Energy consumed in 30 days = 21.26W*1kW/1000W * 30days * 24hr/day = 15.3 kWh
15.3kWh*9.1cents/kWh = 139.3 cents
The cost of energy is closer to double that btw.
13. Assume the values given are RMS:
Power = V^2/Rb = 102.2W
=> Rb = 158.3^2/102.2 = 245.2 Ohms where Rb is the resistance of the light bulb.
Power = V^2/Rb = 72.2^2/Rb = 21.26W
=> Energy consumed in 30 days = 21.26W*1kW/1000W * 30days * 24hr/day = 15.3 kWh
15.3kWh*9.1cents/kWh = 139.3 cents
The cost of energy is closer to double that btw.