Four identical particles, each with mass m = 10-6 kg and charge Q = 10-6 C, are initially at the four corners of a square with side-length a = 0.01 m. If all four particles are simultaneously released from rest, what is their speed when they are a large distance apart? If only one particle is released from rest, while the other three remain stationary at the three other corners of the square, what is the final speed of the released particle once it is very far away?