1. The problem statement, all variables and given/known data Block A (2.1kg) is moving at 7.8 m/s to the right and collides head on with block B (3.4kg), which is moving at 4.2 m/s to the left. a) What is the velocity (magnitude and direction) of the blocks after the collision, if the two blocks stick together? b) What is the impulse (magnitude and direction) of block B on block A during the collision? 2. Relevant equations m1v1 + m2v2 = (m1 +m2)(vf) 3. The attempt at a solution a)I plugged in known values ((2.1)(7.8)+(3.4)(-4.2))=(5.5)vf vf=0.382 to the right, since the number was positive b)I'm not sure where to start.