Two cars collide head-on on a level friction-free road. the collision was completely inelastic and both cars quickly came to rest during the collision. what is true about the velocity of this system's center of mass? select one: a. it was never zero. b. it was always zero. c. it was not zero, but ended up zero. d. none of the above.

Two particles of masses m and 2m are placed on a smooth horizontal table. a string, which joins these two masses, hangs over the edge supporting a pulley, which suspends a particle of mass 3m.the pulley has negligible mass. the two parts of the string on the table are parallel and perpendicular to the edge of the table. the hanging parts of the string are vertical. find the acceleration of the particle of mass 3m.

Carbon-14 is a radioactive element that undergoes beta decay. which force is responsible for allowing carbon-14 to become stable? electromagnetic gravitational weak nuclear strong nuclear

Are formed where bumps from two surfaces come into contact ?