As earth rotates about it’s axis, it takes three hours for the united states to pass beneath a point above earth that is stationary relative to the sun. what is wrong with the following scheme? to travel from washington, d. c. to san francisco shoving very little fuel, simply ascend in a helicopter high over washington, d. c. and wait three hours until san francisco passes below

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?