A proton (mp=1.67x10-27 kg, qp=+e=1.6x10-19 C) and an alpha particle (m=6.64x10-27 kg, q=+2e=2x1.6x10-19 C) are initially at rest and separated by a distance of ri=4.0x10-15 m and they are both released simultaneously.
Find an expression of their speeds when they are separated by a large distance (r=infinity).