Which are the simplest pure substances that cannot be broken down into any other substances

Asap i'm in class rn a 1,000-kg car is traveling 20 m/s on a flat stretch of road. it gets to a hill and coasts uphill until it stops. how high up the hill does the car travel? givens: equation: 1/2mv2initial=mghfinal solve for h. plug & chug, label.

How are the crust and the inner core alike? a) they are both solid. b) they both have the same temperature. c) they are both under the same pressure. d) they are both very close to the center of the earth.

The electric potential a distance r from a small charge is proportional to what power of the distance from the charge? a. r^-1 b. r c. r^-2 d. r^2