An 11.0-w energy-efficient fluorescent lightbulb is designed to produce the same illumination as a conventional 40.0-w incandescent lightbulb. assuming a cost of $0.111/kwh for energy from the electric company, how much money does the user of the energy-efficient bulb save during 220 h of use?

Adielectric-filled parallel-plate capacitor has plate area a = 30.0 cm2 , plate separation d = 9.00 mm and dielectric constant k = 3.00. the capacitor is connected to a battery that creates a constant voltage v = 15.0 v . throughout the problem, use ϵ0 = 8.85x10-12 c2/n.m2 . find the energy u1 of the dielectric-filled capacitor.