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I need help with these questions on this page.

Suppose you're watching a baseball game in your home with the air conditioner

turned on. The air conditioner draws 18A at 220-V from an AC line. The connecting copper

wire has a diameter of 1.628mm. Assume the resistivity of copper is 1.68x10^-8

Ohm*m.

 

(a) How much power does the air conditioner draw?

(b) If the length of the wire is 3.5m, how much power is dissipated in the wire?

(c) Suppose a different wire was used, with a diameter of 2.053mm. The resistance in the wire

is measured to be 6 milli-Ohms at room temperature (20 degrees Celsius). If the new wire

heats up to 90 degrees Celsius, what is the new resistivity value of copper at that temperature?

Assume the thermal coefficient for copper is 0.0068 (inverse Celsius).

(d) If the air conditioner runs for 12 hours that day, how much money would it have cost to use

the air conditioner that day if the electric company charges 12 cents per kWh?