two objects are moving in the xy plane. no external forces are acting on the objects. object a has a mass of 3.2 kg and has a velocity of v= (2.3m/s)i + (4.2m/s)j and object b has a mass of 2.9kg and has a velocity of v=(-1.8m/s)i = (2.7 m/s)j. sometime later object a is seen to have a velocity va=(1.7m/s)i+(3.5m/s)j what is the velocity of object bat that instant