Two equally charged particles, held 22.4 cm apart, are released from rest. The initial acceleration of the first particle is observed to be 4.0 m/s2 and that of the second particle is 6.0 m/s2. If the mass of the first particle is 3.40 x 10-7 kg, determine the mass of the second particle in kg. Give your answer in the form "a.bc x 10^(y) kg".