HW#6: pg. 57-58 Rev 7 – 9, CST 7 – 9
Rev 7 – 9
7. How did Tycho Brahe contribute to the development of Kepler's laws?
8. Briefly describe Kepler's three laws of planetary motion.
9. If radio waves cannot be reflected from the Sun, how can radar be used to find the distance from Earth to the Sun?
CST 7 – 9
7. If Earth's orbit around the Sun were twice as large as it is now, the orbit would take (a) less than twice as long; (b) two times longer; (c) more than two times longer to traverse.
8. Figure 2.21 ("Gravity"), showing the motion of a ball near Earth's surface, depicts how gravity (a) increases with altitude; (b) causes the ball to accelerate downward; (c) causes the ball to accelerate upward; (d) has no effect on the ball.
9. If the Sun and its mass were suddenly to disappear, Earth would (a) continue in its orbit; (b) suddenly change its orbital speed; (c) fly off into space; (d) stop spinning.