With a 1220–W toaster, how much electrical energy is needed to make a slice of toast (cooking time = 1.3 minute)?
At 12.1 cents/kW·h, how much does this cost? (You do not need to enter any units.)
energy= power*timeinsecond=1220*60*1.3 Joules
cost=1.22Kw*1.3/60 hr * 12.1 cents/kwhr
1220 Joules/second * 1.3*60 seconds
= 95,160 Joules
1.220 kW * 1.3 min * 1 hr/60 min
= .0264333333333..... kW h
* 12.1 cents = .32 cents
To calculate the electrical energy needed to make a slice of toast, we can use the formula:
Energy (in kilowatt-hours) = Power (in kilowatts) × Time (in hours)
First, let's convert the cooking time to hours. Since 1 hour = 60 minutes, we have:
Time = 1.3 minutes ÷ 60 minutes/hour
Time = 0.0217 hours (rounded to 4 decimal places)
Now, we can calculate the electrical energy:
Energy = 1.22 kilowatts × 0.0217 hours
Energy = 0.02647 kilowatt-hours (rounded to 5 decimal places)
To calculate the cost, we can multiply the energy consumption in kilowatt-hours by the cost per kilowatt-hour:
Cost = Energy (in kilowatt-hours) × Cost per kilowatt-hour
With a cost of 12.1 cents/kW·h, or $0.121/kW·h, we have:
Cost = 0.02647 kilowatt-hours × $0.121/kW·h
Cost = $0.00320 (rounded to 5 decimal places)
Therefore, it would cost approximately $0.00320 to make a slice of toast using a 1220-W toaster.
To calculate the electrical energy needed to make a slice of toast, you can use the formula:
Energy (in kilowatt-hours) = Power (in kilowatts) x Time (in hours)
First, convert the power of the toaster from watts to kilowatts by dividing by 1000:
Power (in kilowatts) = 1220 W / 1000 = 1.22 kW
Next, convert the cooking time from minutes to hours by dividing by 60:
Time (in hours) = 1.3 minutes / 60 = 0.0217 hours
Now, plug in the values into the formula:
Energy (in kilowatt-hours) = 1.22 kW x 0.0217 hours = 0.0265 kilowatt-hours (kW·h)
To calculate the cost, multiply the energy usage in kilowatt-hours by the cost per kilowatt-hour:
Cost = Energy (in kilowatt-hours) x Cost per kilowatt-hour
In this case, the cost per kilowatt-hour is given as 12.1 cents/kW·h. However, we need to convert it to dollars, so divide by 100:
Cost per kilowatt-hour = 12.1 cents / 100 = $0.121/kW·h
Now, multiply the energy usage by the cost per kilowatt-hour:
Cost = 0.0265 kW·h x $0.121/kW·h = $0.0032
Therefore, the cost to make a slice of toast using a 1220-W toaster for 1.3 minutes is approximately $0.0032.