Write the data down:
I = 15 A
V = 240 V
t = 55 minutes
7x a month
Calculate the electric power output of the dryer:
P = I x V
P = 15 x 240
P = 3,600 W
Convert 55 minutes in seconds:
55 minutes x 60 seconds = 3,300 seconds
Since the dryer is used 7 times a month the total time it will be on is:
T = 7 x 3,300
T = 23,100 s
So the energy cost will be:
E = P x T
E = 3,600 X (23,100)
E = 83,160,000 J
Or in scientific notation we have: