An electric stove with four burners and an oven is used in preparing a meal as follows. Burner 1: 20 minutes Burner 2: 40 minutes Burner 3: 15 minutes Burner 4: 45 minutes Oven: 30 minutes If each burner is rated at 1.1 kW and the oven at 2.5 kW, and electricity costs 12 cents per kWh, calculate the cost of electricity used in preparing the meal. slader

Answer :

abidemiokin

Answer:

41.4 cents

Explanation:

The Quantity of heat used  up is expressed as H = Power * Time

For Burner 1;

Power rating= 1.1kW

Time used = 20mins = (20/60)hr

Time (in hour) = 1/3 hr

H = 1.1* 1/3

H = 11/10*1/3

H = 11/30kWh

For Burner 2;

Power rating= 1.1kW

Time used = 40mins = (40/60)hr

Time (in hour) = 2/3 hr

H = 1.1* 2/3

H = 11/10*2/3

H = 22/30kWh

H = 11/15 kWh

For Burner 3;

Power rating= 1.1kW

Time used = 15mins = (15/60)hr

Time (in hour) = 1/4 hr

H = 1.1* 1/4

H = 11/10*1/4

H = 11/40kWh

For Burner 4;

Power rating= 1.1kW

Time used = 45mins = (45/60)hr

Time (in hour) = 3/4 hr

H = 1.1* 3/4

H = 11/10*3/4

H = 33/40kWh

For Oven;

Power rating= 2.5kW

Time used = 30mins = (30/60)hr

Time (in hour) = 1/2 hr

H = 2.5* 1/2

H = 25/10*1/2

H = 25/20kWh

H = 5/4 kWh

Total Quantity of energy used = 11/30+11/15+11/40+33/40+5/4

Total Quantity of energy used = (44+88+33+99+150)/120

Total Quantity of energy used = 414/120

Total Quantity of energy used = 3.45kWh

If 1kWh costs 12 cents

3.34kWh will costs (12*3.45)cents

3.34kWh will cost 41.4cents

Hence the cost of electricity used in preparing the meal is 41.4 cents

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