Homework Help

An electrical appliance of 2500W is turned on for 2 hours,the cost of electricity...

user profile pic

sherryseah | Student, Grade 9 | Salutatorian

Posted June 3, 2012 at 6:09 PM via web

dislike 1 like

An electrical appliance of 2500W is turned on for 2 hours,the cost of electricity consumption is $1.00. What is the unit cost of electricity?

1 Answer | Add Yours

user profile pic

justaguide | College Teacher | (Level 2) Distinguished Educator

Posted June 3, 2012 at 6:23 PM (Answer #1)

dislike 2 like

An electrical appliance of 2500W is turned on for 2 hours. Power is the rate of consumption of energy per second. One watt is one joule consumed in a second. 1W = 1 J/s.

Electricity consumption is specified in terms of kW*h. An appliance with a power rating of 2500 W or 2.5 kW consumes 2500*2 = 5 kWh in two hours. As the cost of this electricity consumption is $1, the cost of 1 kWh is 1/5 = $0.2

The unit cost of electricity is $0.2 / kWh

Sources:

Join to answer this question

Join a community of thousands of dedicated teachers and students.

Join eNotes