Lamp manufacturer's specifications for a 40 W fluorescent lamp indicate an output of 2680 lumens, a rated life of 20 000 Hr, and a cost of $5.20 per lamp. Data for a 150 W incandescent lamp indicates an output of 2850 lumens, a rated life of 750 hr, and a cost of $2.30 per lamp. When in use, it is anticipated that these lamps will be operated 14 hr per day, 280 days per year.
a. For each lamp, approximate the time period that elapses before replacement is necessary.
b. Approximate the energy and replacement costs of each type of lamp over a 10-year period. Assume use and lamp costs remain constant.