An electric power station that operates at 30 kv and uses a 20: 1 step-up ideal transformer is producing 330 mw (mega-watt) of power that is to be sent to a big city which is located 260 km away with only 2.5% loss. each of the two wires are made of copper (resistivity = 1.72×10^−8 ω.m). what is the diameter of the wires?

You have two photos of a person walking. one shows the person at the corner of third and main streets, the other shows the person at the corner of tenth and main streets. there are lampposts at every corner in this town, and the first picture shows it to be 10: 32: 00 exactly. the second picture shows it to be 10: 49: 30. you know three facts: (1) all of the clocks are synchronized; (2) there are exactly 12 equal-sized blocks per kilometer in this town; and (3) the streets that cross main in this area are numbered consecutively, with no interruptions. what is the person’s average speed in kilometers per hour?