14 7. A nebula is held together by the balance of… A. the outward force of gravity and inward pressure.B. the inward force of gravity and outward pressure.C. high and low kinetic energies.D. high and low temperatures.
15 B. the inward force of gravity and outward pressure. answerB. the inward force of gravity and outward pressure.
16 8. After the solar nebula collapsed, its center became very hot and A. more nebulas formed.B. it formed into a sphere.C. planetesimals formed.D. it exploded.
17 C. planetesimals formed. answerC. planetesimals formed.
18 9. What is the relationship between gravity and pressure in a nebula? Gravity reduces pressurePressure balances gravityPressure increases gravityNone of the above
19 B. Pressure balances gravity answerB. Pressure balances gravity
20 10. Planets began to form as A. planetesimals collided and combined.B. planetesimals flattened into rotating disks.C. temperatures in the solar nebula fell.D. gravity held together the solar nebula.
21 A. planetesimals collided and combined AnswerA. planetesimals collided and combined
22 11. The extra matter at the center of the solar nebula became the A. inner planets.B. moon.C. sun.D. super nova.