The sun is going down, and most of the land is dark, but we can see silhouettes and outlines of objects because some light is still the atmosphere.

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?

How much work would it take to move a coulomb charge across a 4 volt potential difference?

The electric field inside a cell membrane is 8.0mn/c. what's the force on a singly charged ion in this field?