Download Practice Midterm

Practice Midterm
Multiple Choice
1. The ancient Greeks noted that planets
(a) wandered around among the stars
(b) kept step with the stars
(c) were a reddish color
(d) nonsense-- the Greeks didn’t know anything about planets
2. Venus is usually either the “evening star” or the “morning star” because
(a) it is usually on the opposite side of the sun, relative to Earth.
(b) it is usually on the same side of the sun, relative to Earth.
(c) its orbit around the sun is inside Earth’s orbit
(d) its orbit around the sun is outside Earth’s orbit
(e) actually, the evening or morning star is usually Mars, not Venus
3. The most significant difference between the astronomical theories of Ptolemy and
Copernicus is
(a) Ptolemy’s is not based on scientific evidence, while Copernicus’ is.
(b) Ptolemy uses circular planetary orbits while Copernicus uses elliptical orbits.
(c) Ptolemy’s theory is sun-centered, while Copernicus’ is Earth-centered.
(d) Ptolemy’s theory is Earth-centered, while Copernicus’ is sun-centered.
4. Which of these is the correct definition of an ellipse?
(a) Each point on the ellipse is the same distance from one fixed point.
(b) All points on the ellipse are an equal distance apart.
(c) Each pair of points on the ellipse is the same distance from one fixed point.
(d) The sum of the two distances of a point on the ellipse from two fixed points is the
same, for each point on the ellipse.
(e) Each point on the ellipse lies on a smooth oval curve around one fixed point.
5. Tycho Brahe
(a) was the first to propose the theory that the planets move in ellipses around the sun.
(b) made measurements that contradicted Ptolemy’s theory and supported Copernicus’
theory.
(c) made measurements that supported both Ptolemy’s theory and Copernicus’ theory.
(d) made measurements that contradicted both Ptolemy’s theory and Copernicus’ theory.
(e) invented the telescope
6. The most characteristic feature of science is
(a) its precise mathematical relations
(b) its precise quantitative relations
(c) both answers “a” and “b”
(d) the fact that scientific laws are absolutely true, i.e., that they have no exceptions
(e) the mutually supporting relationship between theory and observation
7. Is it possible to prove, for certain, that a scientific theory is true?
(a) Yes, by means of a single confirmed experiment that verifies a theory.
(b) Yes, by carrying out a sufficient number of experimental observations
(c) Yes, by deducing it logically from other scientific theories that are known to be true.
(d) No, because it is always possible that a future experiment will disagree with the
theory
(e) No, because of the experimental error, or uncertainty, that is present in any
experimental result.
8. The Greek model of the atom should be classified as
(a) a useful theory
(b) an experimental fact
(c) an observation
(d) a useless falsehood
(e) a tentative hypothesis
9. The number of atoms in the glucose molecule C6H12O6 is
(a) 3
(b) 4
(c) 24
(d) 48
(e) cannot be determined from the given information
10. In words, 3.5*1011 is
(a) 35 million
(b) 350 million
(c) 3.5 trillion
(d) 35 billion
(e) 350 billion
HINT: write this number out before trying to answer the question
11. At the microscopic level, the difference between gases and solids is that
(a) the gas’s atoms move throughout the gas, while the liquid’s atoms remain near their
original locations
(b) there is much more distance (at least 10 times more) between neighboring atoms in a
gas than in a liquid
(c) in a gas, the individual atoms are larger
(d) both answers “a” and “b” are correct
(e) both answers “b” and “c” are correct
12. What is the similarity between burning and respiration?
(a) both reactions create oxygen
(b) both reactions involve the combination of carbon with oxygen
(c) both reactions consume glucose
(d) both reactions consume energy
(e) actually there is no similarity between them
13. According to Galileo, which of these is “natural” or “unforced” form of motion?
(a) A stone falling straight downward
(b) A book coming to rest as it slides along the floor
(c) Both a stone falling and a book coming to rest as it slides along the floor
(d) Neither a stone falling nor a book coming to rest as it slides along the floor
14. What keeps the moon moving, i.e., why doesn’t the moon slow down and stop?
(a) Earth’s gravity keeps it moving
(b) the sun’s gravity keeps it moving
(c) It is actually slowing down, and will come to rest in a few thousand more years
(d) Nuclear processes operating in the central core of the moon
(e) It is the natural motion of every object to keep moving by itself.
15. You ride a motor scooter 8 km to Marketplace Mall in fifteen minutes. Your
(average) speed is
(a) 32 km/h
(b) 2 km/h
(c) 16 km/h
(d) 4 km/h
(e) 48 km/h
16. While a rock is falling down it has
(a) zero velocity
(b) an unchanging velocity
(c) an increasing velocity
(d) a decreasing velocity
(e) none of the above
17. A “force” could best be described as
(a) something that one body does to another body that keeps the second body moving
(b) something that one body does to another body that causes it to accelerate
(c) something that a body possesses, that enables it to keep moving
(d) something that a body possesses, that enables it to do work
(e) a mystical aura that emanates after midnight from physics laboratories
18. Suppose we subject a golf ball and a more massive lead ball to the same net forces.
Then, compared to the golf ball, the lead ball must have
(a) a smaller acceleration
(b) a larger acceleration
(c) a smaller speed
(d) a larger speed
(e) no one of the above answers is necessarily true
19. A ball is rolling on the floor towards the east, and slowing down as it rolls. As it is
rolling,
(a) the net force on it is to the west
(b) its velocity is towards the west
(c) both of the above
(d) the net force on it is toward the east
(e) the net force on it is zero
20. If you went to the moon, you would find that
(a) it was made of cheese
(b) your weight would be increased
(c) your weight and your mass would be reduced
(d) your mass would be reduced, but not your weight
(e) your weight would be reduced, but not your mass
21. An apple weighing 1 newton is hanging, motionless, from a tree branch. What are
the forces by the environment that act on this apple?
(a) Only the apple’s weight
(b) Only the upward life of the branch
(c) The apple’s weight and the apple’s downward pull on the branch
(d) The apple’s weight and the branch’s upward lift on the apple
(e) There are no forces by the environment on a motionless apple
Problems (Show your work!)
1. Is 1 kilometer closest to 500 meters, 500 feet, or .5 miles? First, show how many
meters, feet, and miles are equivalent to 1 kilometer.
2. It is 6 km to your UR parking space, and you bicycle there in 20 minutes.
What is your average speed (in m/s)?
If you start off from rest and increase to a speed of 4 m/s in the first minute of your
journey, what is your average acceleration during those 60 seconds (in m/(s^2))?
How far will you have traveled in that minute (m)?
If it takes you 19 minutes to travel the remaining distance, what is your average speed for
the rest of the trip (in m/s)?
3. You push your 2 kg physics book along a tabletop, pushing it with 10 newtons of
force.
(a) If the book is greased so that friction is negligible, what is the book’s acceleration?
(b) Suppose the book is not greased, and that the frictional force on it is 4 newtons.
What is the book’s acceleration?
(c) Suppose the book is not greased, and that the frictional force on the book is 11
newtons. What happens to the book?
Short Answer Questions
1. When we say the sun “rises,” what do we really mean?
2. What is the chemical formula for carbon dioxide (one carbon atom and two oxygen
atoms)? Carbon monoxide (one carbon and one oxygen atom)? Methane (carbon and
four hydrogen atoms)? Carbon tetrachloride (“tetra” means “four”)?
3. Two bicyclers pass one another on the same road, traveling in opposite directions.
Could they possibly have the same speed? The same velocity? Explain.
4. (a) Would it be easier to lift your physics book on Earth or on the moon?
(b) Neglecting friction, would it be easier to set the book into horizontal motion on Earth
or on the moon?
(c) Neglecting friction, would it be easier to set the book into horizontal motion on Earth
or in distant space?