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Chapter 2 Reading Guide:
Newton’s First Law of Motion – The Law of Inertia
Name:
Date:
Period:
Complete the Explore! Activity on page 17.
a.
Did the penny remain in place when you pulled the paper?
b. Did the speed with which you pulled make a difference? ________ Explain:
c.
Did the quarter work better than the penny? _______ Why do you think this was so?
2.2) Galileo’s Concept of Inertia (p.18)
1.
What did Galileo show about how lightweight and heavy objects fall?
2. What did Galileo reason about forces being needed to keep a moving object in motion?
3. Define Inertia:
4. Describe how Galileo used a rolling ball on a ramp to show the concept of Inertia.
2.3) Galileo’s Concept of Speed and Velocity
1.
Define Speed in words:
2. Write the equation for Speed:
3. Give three examples of speed units:
4. What is the preferred unit of speed in science?
5. About how fast do you travel on the highway (65 mph) in meters/second?
6. How is Velocity different than Speed?
7. What exactly does the term Constant Velocity mean?
8. Write the question and answer for each Concept Check question on p. 22. ATTACH YOUR OWN PAPER.
Show your work completely.
2.4) Motion is Relative (p 22)
9. Give an example of motion being relative:
2.5) NEWTON’S FIRST LAW OF MOTION – THE LAW OF INERTIA (p 22)
10. Write Newton’s First Law in the box below
11. List at least two real examples of objects showing Inertia.
12. Write the question and answer to the Concept Check question on page 25. ATTACH YOUR OWN
PAPER.
2.6) Net Force – The Combination of All Forces That Act on an Object.
13. Define Net Force:
14. What is the scientific unit for Force
15. Ask your teacher for a Spring Scale . Describe a one Newton force. Describe a 10-newton force.
(What could these forces accomplish?)
16. See the figure at right:
a.
What does the length of each arrow represent?
b. What does the direction of each arrow represent?
c.
Describe how this figure illustrates the concept
of Net Force.
2.7) Equilibrium for Objects at Rest (p 26)
17. Define Equilibrium:
18. What are the two forces acting on this bag of sugar (see diagram at right)?
19. Draw arrows (vectors) on this diagram to show the forces and label the
arrows with the correct force names.
20. Which force is greater, tension in the spring or the weight of the sugar bag? (Trick question).
21. What does the  symbol stand for?
22. State in words what this equation says:
F = 0.
23. See the picture at right (Concept Check, p 28)
a.
If the gymnast hangs with her weight evenly divided between the
two ropes, how would the tension force in both supporting ropes
compare with her weight?
b. Suppose she hangs with slightly more of her weight supported by
the left ring. What would the tension in the right rope be?
2.8) The Support Force – Why We Don’t Fall Through the Floor (p 28)
24. Define/describe the Support Force:
25. What is another name for the support force?
26. Explain what this diagram (at right) is showing;
27. What is the Net Force on a bathroom scale when a 110 pound person stands on it?
28. Suppose you stand on two bathroom scales with your weight
evenly distributed between the two scales. What will each scale
read?
29. How about if you lean and put more of your weight on one scale
than the other?
2.9) Equilibrium for moving objects (p 29)
30. Under what conditions is a moving object in equilibrium?
31. Why can a moving object not be in equilibrium if only one force is acting on it?
32. If a box is pushed at constant velocity, how do we know the amount of friction acting on the box
compared to our pushing force?
33. Complete the Concept Check question on p. 30.