10. A Martian weighs 17 N on the surface of Mars. Calculate his weight on Earth and on the Earth's moon. Does his mass change along the flight from Mars to the Moon to the Earth? The acceleration
due to gravity on Mars is 3.8 m/s’ and the acceleration due to gravity on the Moon is 1.6 m/s?.

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?