Particle 1 has a velocity v= 2 m/s and a mass m= 2 kg. this particle collides with particle 2 of mass m= 6 kg, which is at rest, and then two particles stick together. the speed of the conglomerate particle is
a) 0.5 m/s
b) 0.75 m/s
c) 2 m/s
d) 1.5 m/s
e) 1 m/s