A 150-Watt, 120-volt lamp burns constantly for 8 hours at a rated voltage. What is the energy used in watts/hour?

To understand how to calculate the energy used in watts/hour by a lamp, we start with the power rating of the lamp, which is given as 150 watts. Power is defined as the rate at which energy is used, and in this case, the lamp consumes energy at the rate of 150 watts.

When the lamp burns constantly for a certain time, we can determine the energy used over that period by multiplying the power rating (in watts) by the time (in hours) it operates. In this case, the lamp operates for 8 hours.

The calculation goes as follows:

Energy (in watt-hours) = Power (in watts) × Time (in hours)

So, we perform the calculation:

Energy = 150 watts × 8 hours = 1,200 watt-hours

This means that the lamp uses 1,200 watts of energy over the 8-hour period, which can also be expressed as 1,200 watts/hour of energy usage over that time frame.

Thus, the choice indicating 1,200 watts/hour accurately reflects the energy consumed by the lamp while it operates continuously for the specified duration.