Elastic and Inelastic Collisions - Physics 101 / AP Physics 1 Review with Dianna Cowern

Let's say you have a 1 kg mass moving to the right at 20 m/s that collides with a stationary 2 kg mass and bounces off to move to the left at 10 m/s with the 2 kg mass moving to the right at 5 m/2. The time of collision is the same for both masses, but the net force is different since the impulse or change in momentum on the 2 kg mass is 10 kg*m/s and the impulse or change in momentum on the 1 kg mass is -30 kg*m/s. How does this figure or how is momentum conserved with the momentum lost by the 1 kg mass not being equal with the momentum gained by the 2 kg mass? How can the net forces be different?