A particular household uses a 2.2-kW heater 1.5 h/day ("on" time), four 75-W lightbulbs 5.0 h/day , a 2.5-kW electric stove element for a total of 1.0 h/day , and miscellaneous power amounting to 2.3 kWh/day.

a. If electricity costs $0.105 per kWh, what will be their monthly bill (30 days)?

b. How much coal (which produces 7500 kcal/kg) must be burned by a 37 % -efficient power plant to provide the yearly needs of this household?

Balloon a has charge q, and identical mass balloon b has charge 10q. you hang them from threads near each other. choose all of the statements with which you agree. check all that apply. a. a and b exert the same magnitude forces on each other. b. the force that a exerts on b is 10 times the force that b exerts on a. c. the angle between the thread supporting a and the vertical is < the angle between the thread supporting b and the vertical. d. the force that a exerts on b is 1/10 the force that b exerts on a.