1. The problem statement, all variables and given/known data A spaceship of mass 2.00×10^6 kg is cruising at a speed of 6.00×10^6 m/s when the antimatter reactor fails, blowing the ship into three pieces. One section, having a mass of 4.60×10^5 kg, is blown straight backward with a speed of 2.10×10^6 m/s. A second piece, with mass 8.30×10^5 kg, continues forward at 1.30×10^6 m/s. 2. Relevant equations P1+P2+P3 = P(system) m1(v1)+m2(v2)+m3(v3) = m(total)v(total) 3. The attempt at a solution So, ... I'm thinking this is a conservation of momentum problem... so at first I used the above equations. First off, I tried to find the mass of the third piece (since it's not given, its necessary) which is: M3 = M_t - (m_1 + m_2) = 7.1 x 10^5 kg. Then, I substituted all of the answers into the final equation, which gives me 1.4 x 10^7 m/s. However, this is wrong. Can anyone point me to what I'm missing? Thanks!