Question

A 2100-W hair dryer is operated on a 120-V
circuit for 12 min. If electricity
costs $0.25/kWh, what was the cost (in
cents) of using the blow dryer? Round final
answer to the nearest cent.

Answer 1

Answer:

cost=$15

Explanation:

given;

P= 2100 W

t= 12'= 720 sec=0.2h

V= 120 V

required;

Energy?

cost?

solution;

Energy(kWh) = power*time(in hour)

E=2100*0.2= 420 kWh

cost= 420 kWh* $0.25/kWh

cost= $15

since blow dryer use 120-V