4.1
1. In Newton's insight, what did the moon and the falling apple
have in common?
2. Describe Newton's universal law of gravitation.
3. Write the equation described by the universal law of gravitation.
4. How did Philipp von Jolly measure the universal gravitational
constant?
5. What doe the value of G tell us about the strength of gravity
when compared with electromagnetic and strong and weak nuclear forces?
6. How was the universal law of gravity used to calculate the
Earth's mass?
7. Why is the relationship between gravitational force and distance
called the inverse square law?
8. Harold climbs 3 meters up a tree. When he climbs to twice
the height his weight is practically the same. Why is his weight
not reduced to 1/4 the previous weight?
4.2
9. How does the moon create tidal bulges on the earth's oceans?
10. Illustrate how spring and neap tides are produces.
a.
b.
11. How does Brittany France use tidal power to produce electricity?
4.3
12. Why do astronauts in the international space station have
the sensation of weightlessness?
4.4
13. Compare the terms projectile and trajectory.
14. What is the relationship between vertical and horizontal components
of a projectiles trajectory?
15. Make an illustration that compares horizontal motion with
no gravity, vertical motion with gravity, and both cases combined.
16. What is the name given to the path traced by a projectile
that has horizontal velocity and vertical acceleration?
17. What is the relationship between projectile range and projectile
angles?
18. How does air resistance effect trajectory?
4.5
19. Why are satellites placed at high altitudes?
20. A Why must a projectile have a tangential speed
of 8 km/s to orbit the Earth?
21. Why does a circular orbit create no change in speed--only
change in direction?
22. What is the relationship between the period of a satellite
and its distance from the Earth's center?
23. What kind of path will occur when the speed of a projectile
is greater than that needed for circular orbit?
4.6
24. Make an illustration that compares the potential energy and
the kinetic energy of a satellite in elliptical orbit at apogee and perigee.
4.7
25. What is escape velocity?
26. What is the escape velocity for Earth?
27. Do some research to find out why the space shuttle is launched
towards the east over the Atlantic Ocean and not towards the west.
Hint: Think about how velocity vectors combine.