Posted by Cavin on .
Two balls are approaching each other head on. Their velocities are + 9.55 and 11.0 m/s
(a) Determine the velocity of the center of mass of the two balls if they have the same mass.
(b) Determine the velocity of the center of mass of the two balls if the mass of one ball(v=9.55m/s) is twice the mass of the other ball (v=11.0m/s)
(a) mv1 + mv2 = 2m V
where v is the centerofmass velocity
V = (v1 + v2)/2 = 1.45/2 = 0.725 m/s
(b)2mv1 + v2 = 3m V
solve for V

Physics 
Mike,
The second equation of part be should be 2mv1 + mv2=3mV. 2m(9.55)+(11m)=3mV which is equal to 19.1m11m=3mV which is equal to 8.1m=3mV now divide both sides by 3m (where the m's cancel out)and you get V= 2.7 m/s