Two equally charged particles, held 4.2 x 10-3 m apart, are released from rest. The initial acceleration of the first particle is observed to be 6.8 m/s2 and that of the second to be 10 m/s2. If the mass of the first particle is 5.5 x 10-7 kg, what are (a) the mass of the second particle and (b) the magnitude of the charge (in C) of each particle?