An atom is made of three basic subatomic particles: protons, neutrons, and electrons. which of these carry a charge?
a. proton and neutron
b. proton and electron
c. neutron and electron
d. proton, neutron and electron

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.