STUDY GUIDE FOR TEST 3
Monday October 25
1.
2.
3.
4.
5.
6.
7.
air resistance
gravity
Solving numerical problems with g
falling objects
projectile motion
mass and weight
orbit
The above topics will appear on the test, which will have 20 questions worth
three points each. You will see numerical problems, fill in the blank,
true/false, short answer and essays. You will not be given the equation for
Newton’s Second Law or the value for g.
You will be marked off a ½ point when you do not include units for a
numerical answer or use the wrong units.
Use the following sources to study from:
*lecture notes located on my Wikispace page
*your text. If a topic appears in the text that we did not discuss, then it
will not be included on the test.
*labs
*homework
*additional notes you may have taken in class
***** bring your calculator to the test!!!
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Sample Test
This is a sample test only. You will see questions similar to these on your
test, but you will not see the exact same questions. Complete this test at
home and score it yourself after you have completed it. I will not collect
it and it will not be graded by me. Bring it to class on Friday. We may go
over it together if there are questions.
Please show all your work.
1. What is the acceleration of a 7kg mass if a gravitational force of 68.6
Newtons causes it to fall to Earth?
2. What is the mass of an object accelerating towards the Earth with a
force of 300 Newtons?
3. What is the force of gravity acting on a 200 kg object falling to
Earth?
4. If the surface area of a falling object is large, the force of
______________ will also be large.
a. speed
b. air resistance
c. acceleration
d. distance
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5. Explain Newton’s Law of Gravitation in 3-5 sentences. Include
examples. Spelling and grammar count.
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6. Which pair of objects has more gravitational force between them?
a. two marbles five feet away from each other
b. two marbles ten feet away from each other
c. a marble and a baseball five feet away from each other
d. there is no gravitational force between a marble and a baseball.
7. True or False? All things with mass have gravity.
8. True or False? Air resistance is a force that opposes gravity.
9. True or False? Scientists can create the condition of zero gravity on
Earth.
10. The value of g is:
a. speed
b. acceleration
c. distance
d. time
11. Why is the path of a projectile parabolic? Answer in 1-2 sentences.
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12. Explain the difference between mass and weight in 2 or more
sentences.
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13. What is your weight on Saturn if the value of g on Saturn is 11.2
meters per second squared and your mass is 50 kg?
14. Mercury is smaller than the Earth. If you stood on Mercury, your
weight would be______________ your weight on Earth.
a. More than
b. Equal to
c. Less than
d. Zero compared to
15. Mercury is smaller than the Earth. If you stood on Mercury, your
mass would be ______________________ your mass on Earth.
a. More than
b. equal to
c. less than
d. zero compared to
16. Orbit occurs as a result of __________________ and gravity.
a. horizontal motion
b. free fall
c. air resistance
d. terminal velocity
17. In a vacuum, which would hit the ground first? A chimpanzee or a
banana? Explain why in 3-5 sentences.
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18. In which situation would an object be in free fall?
a. when thrown from a plane
b. in a vacuum
c. when dropped from a building
d. launched from the ground
19. Outside of a vacuum, which object would hit the ground first?
a. You
b. A feather
c. A textbook
d. Our Venus fly trap
20. What could scientists conclude if, when they dropped the feather and
hammer on the Apollo 15 mission in 1971, the hammer hit first? 1-2
sentences.
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Mass in
kilograms
Answers
1. 9.8 m/s/s
2. 30.6 kg
3. 1960 N
4. b
5. Newton’s Law of Gravitation explains that all things have an
attractive force between them. As distance between the two objects
decreases, gravity increases. If the mass of either of the two
objects increases, gravity increases. For example, the attraction
between the Earth and my body is high because the mass of the Earth
is large and I am close to it. The attraction between Jupiter and my
bodyis small because, although Jupiter is larger than the Earth, I am
farther away from it.
6. c
7. T
8. T
9. F
10. b
11. The path of a projectile is curved or parabolic, because of the
combination of the horizontal motion of the object and the vertical
force of gravity.
12. Mass is the amount of matter in an object measured in kilograms.
Weight is a force calculated with Newton’s Second Law. It is
measured in Newtons and is the product of g and mass.
13. 560 N
14. c
15. b
16. a
17. The chimp and the banana would hit the ground together in a vacuum.
There is no air resistance to balance gravity, so both would be in free
fall. Gravitational acceleration in the vacuum is dependent on the
planet you are on, not the mass of the object, so it is the same for
both objects. Both are accelerating at the same rate when they hit
together.
18.b
19.a
20. If the hammer hit first on the moon, scientists might conclude that
was air on the moon. Air resistance would slow down the feather, allowing
the hammer to hit first.
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