Two Jupiter-size planets are released from rest 7.00*1010 m apart. What are their speeds as they crash together?

Applying the equations of motion:

v^2 = u^2 + 2as; where v = velocity before as the two crash, u = initial velocities = 0, a = total gravitational pull for the two Jupiter stars = 24.79*2 = 49.58 m/s^2, s = distance of separation = 7.00*10^10 m.

Substituting;

v^2 = 0 + 2*49.58*7*10^10 = 6.941*10^12 m^2/s^2

v = Sqrt (6.941*10^12) = 2,634,615.72 m/s