If electrical energy costs 12 cents, or $0.12, per kilowatt-hour, then what would the following events cost? (a) Burn a 40 Wlight bulb for 24 h straight. (b) Operate an electric oven for 6.0 hif it carries a current of 20.0 A at 220 V.

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If electrical energy costs 12 cents, or $0.12, per kilowatt-hour, then what would the following events cost?  (a) Burn a 40 Wlight bulb for 24 h straight.  (b) Operate an electric oven for 6.0 hif it carries a current of 20.0 A at 220 V.

Jayden-James Duffy · Accepted Answer

For part a)  We have $0.12 / kW hr @ 24 hours. The Cost formula is: Cost=Power (P)×Time used (Hr)  ×Cost per kW/hr  P=40W→0.040kW  Plug it all into the formula:  Cost = (0.040kW)(24hr)($0.12/kW hr)  Cost = 11.52 cents or $0.12 (when rounded)  For part b)  We have the following information:  $0.12 /kW hr @ 6.0hr  I=20.0A  V=220V  I=PV→P=(V)(I)  P = (220V)(20.0A)  P=4400W→4.4kW  Now use the Cost formula from above in part a.  Cost=Power (P)×Time used (Hr)  ×Cost per kW/hr  Cost = (4.4kW)(6.0hr)($0.12/kW hr)  Cost = 316.8 cents = $3.17 when rounded.

If electrical energy costs 12 cents, or $0.12, per kilowatt-hour, then what would the following events cost? (a) Burn a 40 Wlight bulb for 24 h straight. (b) Operate an electric oven for 6.0 hif it carries a current of 20.0 A at 220 V.

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