1. A moon rocket is accelerating at 4 gees (40 m/s/s). It has mass of 106 kg. How much force is the engine producing?

2. Two hockey players stand on a frictionless surface facing each other. One has mass of 100kg and the other has mass of 50 kg. The small one swings at the large one, his fist exerting 10 Newtons on his opponents nose for 0.1 seconds. The large fellow's nose returns the force equally (Newton #3). How fast is each moving after the encounter?

3. The largest star in our galaxy has a mass of 1032 kg. How long does it take a planet at 1 AU (1.5x1011 m) to orbit?

4. What velocity is required to escape from the solar system, starting at a distance of 1 AU from the Sun? (1AU = 1.5x1011m= Sun/Earth Distance)

5. Explain in your own words why an interstellar cloud that is initially spherical settles into a disk before becoming a star and solar system.