Each unit of electricity costs 0.8$, how much does it cost to run a 500W appliance for 4 hours?​

What is the approximate amplitude of this wave a.10 seconds b.15 centimeters c.30 centimeters d.15 seconds

The consumption of fossil fuels could be

The electric field between square plates of a parallel-plate capacitor has magnitude e. the potential across the plates is maintained with constant voltage by a battery as they are pulled apart to twice their original separation, which is small compared to the dimensions of the plates. the magnitude of the electric field between the plates is now equal to a)e b)e/4 c)e/2 d)4e e)2e