1. A net force of 2000N act on a rocket of mass 1000. kg. How long must the force be applied in order to increase the rockets velocity from 10.0 m/s to 200.0 m/s.
2. Marble A, mass 5.0 g, moves at a speed of 20.0cm/s. It collides with a second marble, B, mass 10.0 g, moving at 10.0cm/s in the same direction. After collision, marble A continues with a speed of 8.0 cm/s in th same direction. (a) calculate the marbles' momenta before the collision 9b0 calculate the speed of marble B after the collision.