How are earthworms connected with soil fertility? a) they eat essential nutrients and reduce the fertility of the soil. b) they increase soil fertility by fixing nitrogen compounds in the soil. c) they increase soil fertility by converting dead leaves into rich humus. d) they convert minerals in the soil to compounds that are harmful to plants.

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.