A 10kg toy truck has a 5kg toy car at rest. If the toy truck was moving at 3 m/s before the collision and carries that car with it, what is the Final velocity of the car and truck.
A. 15 m/ s
B. 30 m/ s
C 2 m/ s
D. 18 m/ sc free

Working alone at its constant rate, pump x pumped out ¼ of the water in a tank in 2 hours. then pumps y and z started working and the three pumps, working simultaneously at their respective constant rates, pumped out the rest of the water in 3 hours. if pump y, working alone at its constant rate, would have taken 18 hours to pump out the rest of the water, how many hours would it have taken pump z, working alone at its constant rate, to pump out all of the water that was pumped out of the tank? a) 6b) 12c) 15d) 18e) 24