Final answer:
To make a slice of toast in a 1200-W toaster for 1 minute, it would require 1200 joules of electrical energy. At a cost of 9.0 cents/kWh, the cost to make one slice of toast is approximately 0.002997 cents.
Step-by-step explanation:
To calculate the electrical energy needed to make a slice of toast in a 1200-W toaster in 1 minute, we need to first convert the power to watts per minute. Since the cooking time is given as 1 minute, the power consumption would be 1200 watts. So, the electrical energy used is 1200 joules (J). To find the cost, we can convert this energy from joules to kilowatt-hours (kWh) by dividing by 3600000 (1 kWh = 3600000 J). In this case, the energy consumption is 0.000333 kWh. To calculate the cost, we multiply the energy consumption by the cost per kWh, which is 9.0 cents/kWh. The cost to make a slice of toast is approximately 0.002997 cents.