1. A proton, moving to the left at 7.0 x 106m/s collides with a neutron (mass approx. same as that of the proton) moving at 4.0x106m/s to the right to form a deuteron. Find the velocity of the deuteron. 2. Total momentum before collision = Total momentum after collision 3. 7.0 x 106m/s - 4.0x106m/s = v v= 3.0x106m/s. This is an inelastic collision Could someone check that please?