Athin rod of length l and mass m rotates around an axis that passes through a point one-third of the way from the left end.1) which of the following will decrease the rotational kinetic energy of the rod by the greatest amount? a) decreasing the mass of the rod by one fourth, while maintaining its length. b) decreasing the length of the rod by one half, while maintaining its mass. c) decreasing the angular speed of the bar by one half. d) each of the above scenarios will decrease the rotational kinetic energy by the same amount.

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?