If a 100-W light bulb is left on for 48hrs..and electricity costs 12 cents/kWh....how much would that cost?

Question

I have this as a homework question and i'm stumped by the /kWh

Answer 1

1 kWh (kilowatt-hour) is equal to 100 Watt-hours. Therefore, 100W is equal to 1kWhr. Therefore, 12 cents times 1 times 48 is $5.76

Answer 2

100w x10 = 1000 w = 1kw

100w X48 =4800 w = 4.8kw

4.8 X .12 = 57.6 cents

57.6 cents or 58 cents

or

$.576 / $.58

Answer 3

You have to convert the watts into kilowatts by moving the decimal point to the left three places, making it .1

12 x .1 = 1.2 cents every hour

1.2 x 48 = 57.6 cents

Answer 4

Convert the watt hours into kilowatt hours. Dimensional analysis.  

Answer 5

A kilowatt hour is the consumption of 1000 watts in one hour, or its equivalent. (10 watts for 100 hours = 1 kWh)

So figure how many kilowatts are used and multiply by $0.12.

Regards,

Dan

PS Pacboy is off by one order of magnitude.

Answer 6

Hmmmm let see

100W X 48Hrs = 4800 Watt Hrs or 4.8KW hrs (1KW = 1000Watts)

So

4.8KW x .12 = .576 or 58 cents...hmmm i dont know for sure