Earth Science Courses
1. Briefly, what is science?
2. Define the following terms;
scientific fact
hypothesis
scientific law
theory
3. In daily life, people are often praised for maintaining some particular point of view, for the “courage of their convictions.” A change of mind is seen as a sign of weakness. How is this different in science?
4. Why do many people believe they must choose between science and religion?
5. What name (physical term) is given to the property by which objects resist changes in motion?
6. What is the difference between weight and mass?
7. Where is your weight greater, on Earth or on the Moon? How about your mass?
8. One kilogram (mass) weighs 9.8 N on Earth. Would it weigh more or less on the moon?
9. What is the net force on a box pushed to the right with 50 N (Newtons) of force, while being pushed to the left with 20 N of force?
10. What two quantities are necessary for a vector quantity?
11. If we push an object at constant velocity, how do we know how much friction acts on the object compared to our pushing force?
12. Suppose you push to the right on a piece of heavy furniture, but not hard enough to make it slide. Does a friction force act on the furniture?
13. List three types of friction and “generally” discuss which is strongest and weakest of the three.
14. Distinguish between speed and velocity.
15. Why do we say velocity is a vector and speed is not?
16. Distinguish between speed and acceleration.
17. What is the acceleration of an object that moves at constant velocity? What is the net force on the object in this case?
18. What is the acceleration of an object in free fall at Earth’s surface?
19. State the law of inertia.
20. What kind of path would the planets follow if suddenly their gravitational attraction to the Sun no longer existed?
21. State Newton’s second law in general terms (using mass “m” as a term) and state it again (using weight “w” as a term).
22. Is acceleration directly proportional to force, or is it inversely proportional to force? Give an example. Is acceleration directly proportional to mass, or is it inversely proportional? Give an example.
23. If the mass of a sliding block is tripled at the same time that the net force is tripled, how does the resulting acceleration compare to the original acceleration?
24. What is the net force that acts on a 10-N falling object when it encounters 4 N of air resistance? What if it encountered 10 N of air resistance?
25. State Newton’s third law?
26. Consider hitting a baseball with a bat. If we call the force on the bat against the ball the action force, identify the reaction force.
27. If the force that acts on a cannonball and the recoiling cannon from which it is fired are equal in magnitude, why do the cannonball and the cannon have very different accelerations?
28. Briefly summarize Newton’s three laws of motion.
29. Which has greater momentum, an automobile at rest or a moving skateboard?
30. Cite an example in which a force is exerted on an object without doing work on the object.
31. Which, if either, requires more work- lifting a 50-kg sack a vertical distance of 2-m or lifting a 25-kg sack a vertical distance of 4m.
32. A car is raised a certain distance in a service-station lift and therefore has potential energy relative to the floor. If it were raised twice as high, how much potential energy would it have?
33. Two cars are raised to the same elevation on service-station lifts. If one car is twice as massive as the other, how do their potential energies compare?
34. A moving car has kinetic energy. If it speeds up until it is going four times as fast, how much kinetic energy does it have in comparison to its original speed?
35. An apple hanging from a limb has potential energy because of its height. If the apple falls, what becomes of this energy just before it hits the ground? When it hits the ground?
36. If a machine multiplies force by a factor of four, what other quantity is diminished, and by how much?
37. What is the ultimate source of energies for the burning of fossil fuels, dams, and windmills?
38. What is the ultimate source of geothermal energy?
39. State Newton’s law of universal gravitation in words. Then do the same with one equation
