The motion of a small ball floating on a pond when waves travel across the ponds

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?

Apropagating wave in space with electric and magnetic components. these components oscillate at right angles to each other. it may travel in a vacuum.

Whithin which type of system is neither the total mass nor the total energy conserved ? a. open b. connected c. isolated d. closed