Download Vocabulary Chapter 3: Newton`s Second Law of Motion

Name: _______________________________ Date: __________________ Hour: __________________
Vocabulary
Chapter 3: Newton’s Second Law of Motion- Force and Acceleration
Read the following passage carefully and use context clues to determine the
meaning of the underlined words. Italicized words may be unfamiliar as well- use
context clues or look them up as needed.
In addition to speed and velocity, Galileo developed another property of moving
objects through his experiments with inclined planes. He found that balls rolling down
inclines rolled faster and faster. Their speed changed as they rolled. He further noticed
the balls gained the same amount of velocity in equal time intervals. You experience
what Galileo called acceleration every time you ride in a car; because the velocity of
the car changes as you accelerate or decelerate. When a car turns, even if the speed
does not change, it is accelerating because the car’s direction is changing (change in
velocity). Acceleration is also directly proportional to net force. This means that when a
force is applied with or against an object’s motion, the object will
experience a change in velocity.
If you kick an empty can you will notice it will accelerate
much more than a can filled with rocks. The most massive, full
can has more inertia than the empty can (it is most resistant to
the change in motion). This suggests that the mass of an object
corresponds to its inertia. A dense material, such as lead, has a
lot more mass and therefore more inertia than a less
dense material such as Styrofoam. Often times mass is confused with weight.
You will weigh less on the moon than on Earth, but your mass will remain the
same. Even though weight and mass are different from each other, they are
directly proportional to each other. Objects with large masses have large
weight; objects with little mass have little weight.
Acceleration is inversely proportional to mass. Experiments show that if
force is the same, an object that has twice the mass of another object will have
results with half of the acceleration. Newton’s Second Law is written as the following
equation:
Acceleration = net force
mass
Write his law using the words “inversely” and “directly” proportional.
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We know from Galileo’s previous experiments, dropping different
massed objects from the leaning tower of Pisa; that no matter the mass
objects fall at the same time. We can say that the mass of the object and
air drag do not affect it when it is in free fall. Downward-falling objects
gain speed because of gravity. When air is present, the downward net
force = weight – air drag. When the net force builds up to equal the weight
the object has reached its terminal velocity.
1. Acceleration
a. I think the word acceleration means: ______________________________
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b. Have you heard the word acceleration used before? _________________
Where? ____________________________________________________
c. The definition of acceleration is __________________________________
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d. I could use acceleration in the following sentence (situation): __________
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2. Mass
a. I think the word mass means: ___________________________________
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b. Have you heard the word mass used before? ______________________
Where? ____________________________________________________
c. The definition of mass is _______________________________________
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d. I could use mass in the following sentence (situation): ________________
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3. Weight
a. I think the word weight means: __________________________________
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e. Have you heard the word weight used before? ______________________
Where? ____________________________________________________
f. The definition of weight is ______________________________________
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g. I could use weight in the following sentence (situation): _______________
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4. Inversely
a. I think the word inversely means: ________________________________
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h. Have you heard the word inversely used before? ____________________
Where? ____________________________________________________
i. The definition of inversely is ____________________________________
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j. I could use inversely in the following sentence (situation): _____________
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5. Free Fall
a. I think free fall is: _____________________________________________
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b. Have you heard free fall used before? ____________________________
Where? ____________________________________________________
c. The definition for free fall is: ____________________________________
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d. I could use free fall in the following sentence (situation): ______________
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6. Terminal Velocity
a. I think the word terminal velocity means: __________________________
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b. Have you heard the word terminal velocity used before? ______________
Where? ____________________________________________________
c. The definition of terminal velocity is ______________________________
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d. I could use terminal velocity in the following sentence (situation): _______
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Chapter 3 Review Questions
Read pg. 35- 48 in your book
Answer the following questions in COMPLETE SENTENCES!
1. Distinguish between velocity and acceleration.
2. What is the acceleration of free fall?
3. What relationship does mass have with inertia? With weight?
4. If the mass of a sliding object is somehow tripled at the same time the net force
on it is tripled, how does the resulting acceleration compare to the original
acceleration?
5. Suppose you exert a horizontal push on a crate that rests on a level floor, and it
doesn’t move. Hoe much friction acts compared with your push? As you increase
your push, will friction on the crate increase also? Once the crate is sliding, how
hard do you have to push to keep it moving at a constant velocity?
6. Why doesn’t a heavy object accelerate more than a light object when both are
freely accelerating?
7. What is the net force on a bright red Mercedes convertible traveling along a
straight road at a steady speed of 100km/hr?
8. Your empty hand is not hurt when it bangs lightly against a wall. Why is it hurt if it
does so while carrying a heavy load? Which of Newton’s laws is most applicable
here?
9. When a junked car is crushed into a compact cub, does its mass change? Its
weight? Its volume? Explain.
10. Why is it that Justin Beiber “accidently” falls from the top of a 50-story building his
the ground no faster than if he falls from the 20th?