Telephone companies are replacing older, analog lines with digital lines because
a. wireless transmissions can be used only for short distances. b. computers can now be equipped with modems to translate transmissions. c. digital lines are less expensive. d. data is transmitted more quickly over digital lines.

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.