What is magnetic field reversal? A. When earth’s magnetic field leaves the South Pole and enter the North Pole
B. When earth’s magnetic field suddenly disappears for short periods of time
C. When earth’s magnetic field leaves the North Pole and enters the South Pole
D. When earth’s magnetic field suddenly runs east/west instead of south/north

The passing of heat through a material while the material itself stays in place. a. radiation b. conduction c. convection

Properties seen when one one substance changes to another are known as properties

Two cannon balls weighing 18 kg and 24 kg are chained together and fired horizontally with a velocity of 165 m/s from the top of a 21-m wall. the chain breaks during the flight of the cannonballs and the 18-kg cannonball strikes the ground at t = 1.5 s, at a distance of 240 m from the foot of the wall, and 7 m to the right of the line of fire. determine the position of the other cannonball at that instant. neglect the resistance of the air.