A long wire with a radius of 0.450 cm carries a current. The potential difference across a 2.60 m long section of this wire is 14.0 V, and the wire carries a current of 0.350 A. (a) What is the resistance (in Q2) of the 2.60 m long section of wire? (b) What is the resistivity (in Q2 m) of the wire? Need Help? Read It In a particular town, electrical energy costs $0.12 per kilowatt-hour. (Round your answers, in dollars, to at least two decimal places.) (a) How much does it cost to operate an old-style incandescent 100-W light bulb continuously for 24 hours? $ (b) A modern LED light bulb that emits as much visible light as a 100-W incandescent only draws 16.0 W of power. How much does it cost to operate this bulb for 24 hours? $ (c) A particular electric oven requires a potential difference of 220 V and draws 20.0 A of current when operating. How much does it cost to operate the oven for 3.00 hours? $ A car owner forgets to turn off the headlights of his car while it is parked in his garage. If the 12.0-V battery in his car is rated at 79.0 A h and each headlight requires 40.8 W of power, how long will it take the battery to completely discharge? hours Birds resting on high-voltage power lines are a common sight. The copper wire on which a bird stands is 2.3 cm in diameter and carries a current of 48 A. If the bird's feet are 4.3 cm apart, calculate the potential difference between its feet. (The resistivity of the wire is 1.7 10-8. m) Electric current passing through a human body can be dangerous, even fatal, depending on the amount of current, the duration of the current, and the region of the body through which the current passes. However, currents less than about 0.5 mA are typically imperceptible. A current caused by a low potential difference typically travels through the outer layer of the skin. The resistance of the skin therefore determines how much current flows for a given potential difference. The resistance can be influenced by a number of factors, including whether the skin is wet or dry. For example, suppose an electric current of 75.5 A follows a path through the thumb and index finger. When the skin is dry, the resistance along this path is 3.00 x 105 Q. What voltage (in V) is required for this current, in the case of dry skin? V When the skin is wet, the resistance is lowered to 1,750 Q. What voltage (in V) is required for the same current, in the case of wet skin? V