Planets are not uniform inside. normally, they are densest at the center and have decreasing density outward toward the surface. model a spherically symmetric planet, with the same radius as the earth, as having a density that decreases linearly with distance from the center. let the density be 1.20×104 kg/m3 at the center and 2100 kg/m3 at the surface. what is the acceleration due to gravity at the surface of this planet?

g= ? m/s^2

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?