12:06 PM webassign.net TFVV * 60% A certain waffle iron is rated at 0.75 kW when
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12:06 PM webassign.net TFVV * 60% A certain waffle iron is rated at 0.75 kW when connected to a 120-V source. (a) What current does the waffle iron carry? (b) What is its resistance? The cost of energy delivered to residences by electrical transmission varies from $0.070/kWh to $0.258/kWh throughout the United States; $0.110/kWh is the average value. (a) At this average price, calculate the cost of leaving a 75-W porch light on for two weeks while you are on vacation? (b) At this average price, calculate the cost of making a piece of dark toast in 3.00 min with a 915-W toaster? (c) At this average price, calculate the cost of drying a load of clothes in 40.0 min in a 5.00103-W dryer? Batteries are rated in terms of ampere-hours (A·h). For example, a battery that can produce a current of 2.00 A for 3.00 h is rated at 6.00A h. (a) What is the total energy stored in a 9.0-V battery rated at 45.0 A h? kWh (b) At $0.0770 per kilowatt-hour, what is the value of the electricity produced by this battery? Home My Assignments Extension RequestExplanation / Answer
11.
a)
Average cost of 1Kwh = $0.110
75W is used for 2 weeks
Now, in 2 weeks, = 14days , no. of hours = 14 * 24 hours = 336 hours
Total Energy consumed by porch light = 75W * 336 hours = 25200 Wh = 25.2 KWh
Average cost of 1Kwh = $0.110
Cost of 25.2Kwh = $0.110 * 25.2 = $ 2.772
b)
Time in hours = 3/60 = 0.05 hours
Total Energy consumed by 915W toaster = 915 W * time in hours = 915 W * 0.05 h =45.75 Wh = 0.04575 KWh
Average cost of 1KWh = $0.110
for 0.04575 KWh, cost = $ 0.005032
c)
No. of hours = 40/60 = 0.666 hours
No. of KWs in dryer = 5 KW
no. of KWh = 5 * 0.666 = 3.33 KWh
Average cost of 1KWh = $0.110
for 3.33KWh,cost = 0.110 * 3.33 = $ 0.366
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