Practice Final Physics 101

PRACTICE FINAL
1) You give your physics book a quick push so that it slides along a table top. It soon slides to a
stop. How would Aristotle and Galileo interpret this?
A) Aristotle says this is just the natural motion of the book, but Galileo says the force of
friction slows it to a stop.
B) Aristotle says the force of friction slows it to a stop, but Galileo says this is just the
natural motion of the book.
C) Both of them say that this is just the natural motion of the book.
D) Both of them say the force of friction slows it to a stop.
E) They agree that physics books can make you crazy and it's best not to think about
them.
Answer: A
2) According to Newtonian physics, an object with no forces acting on it must
A) fall.
B) eventually come to rest.
C) be at rest.
D) either be at rest or have constant velocity.
E) be accelerated, with an unchanging acceleration.
Answer: D
3) In what way did Galileo improve on the physics of Aristotle?
A) Galileo understood that energy is always conserved in every physical process.
B) Galileo understood that the gravitational force acts between every pair of objects in the
universe.
C) Galileo understood that no force is needed to keep an object moving in a circle at
constant speed.
D) Galileo understood that a force is needed to keep an object moving at constant velocity.
E) Galileo understood that "natural" (or unforced) motion occurs at constant velocity.
Answer: E
4) In the "space" [or in "outer space"] between Earth and the moon there is
A) no air and no force [or pull] due to gravity.
B) both air and a force due to gravity.
C) air, but no force due to gravity.
D) no air, but there is a force due to gravity.
E) a big cloud made of chocolate fudge.
Answer: D
1
9
)
The figure shows a ball tied to a string and swung in a circle, clockwise. If the string
suddenly breaks when the ball is in the position shown, which arrow best represents the
initial direction of motion of the ball just after the string breaks?
A) Arrow A.
B) Arrow B.
C) Arrow C.
D) Arrow D.
E) Arrow E.
Answer: A
5) A ball is moving at 20 m/s. If no forces act on it, then 5 seconds later the ball's speed will be
A) zero.
B) more than 20 m/s, but the precise answer cannot be found without further information.
C) less than 20 m/s, but the precise answer cannot be found without further information.
D) 20 m/s.
E) None of the above.
Answer: D
6) You ride a motor scooter 8 km in 15 minutes. Your [average] speed is
A) 32 km/hr.
B) 2 km/hr.
C) 16 km/hr.
D) 4 km/hr.
E) 48 km/hr.
Answer: A
7) You ride a motor scooter 8 km in 10 minutes. Your speed is
A) 32 km/hr.
B) 24 km/hr.
C) 16 km/hr.
D) 40 km/hr.
E) None of the above.
Answer: E
8)
The figure represents a multiple-flash photo of two balls moving to the right, and shows
both balls at several numbered times. The time between flashes is 0.20 s, and the large
divisions on the measuring rod are centimeters. The speed of the lower ball is
A) 0.4 cm/s.
B) 0.8 cm/s.
C) 1.2 cm/s.
D) 4.8 cm/s.
E) 6 cm/s.
Answer: E
9) An artificial satellite moves at a steady 25,000 km/hr in a circular orbit around Earth. Is it
accelerated?
A) Yes, because its speed is changing.
B) Yes, because its direction of motion is changing.
C) No, because its speed is unchanging.
D) No, because its direction of motion is unchanging.
E) No, for both reasons "C" and "D".
Answer: B
10) An auto is moving at a steady 50 mph up a long straight [constant "slope"] incline. While it is
on this incline,
A) its velocity and acceleration are both zero.
B) its velocity is zero but its acceleration is not zero [i.e. it does have an acceleration].
C) its acceleration is zero but its velocity is not zero.
D) neither its velocity nor its acceleration are zero.
E) it has the heebie-jeebies.
Answer: C
11) An object is not accelerated if
A) its speed changes while its direction of motion remains unchanged.
B) its speed remains unchanged while its direction of motion changes.
C) it is acted upon by an external influence.
D) its speed and its direction of motion are both unchanging.
E) both answers "B" and "D" are correct.
Answer: D
12) While a rock is falling straight down it has
A) zero acceleration.
B) a constant [or unchanging] acceleration.
C) an increasing acceleration.
D) a decreasing acceleration.
E) none of the above.
Answer: B
13) In which of the following cases does the automobile have an acceleration?
A) An auto moving along a straight (or steady) upward incline at constant speed.
B) An auto rounding a curve at constant speed.
C) Both of the above.
D) None of the above.
Answer: B
14) A car is rounding the top, or crest, of a hill while moving at a steady 50 km/hr. What can you
say about this car's acceleration, and why?
A) The car is accelerated, because its speed is changing.
B) The car is accelerated, because its direction of motion is changing.
C) The car is not accelerated, because its direction of motion is not changing.
D) The car is not accelerated, because its speed is not changing.
E) The car is not accelerated, because neither its direction of motion nor its speed are
changing.
Answer: B
15)
The figure represents a multiple-flash photo of two balls moving to the right, and shows
both balls at several numbered times. In the figure,
A) both balls are accelerated, and the upper ball is moving fastest.
B) neither ball is accelerated, and the upper ball is moving fastest.
C) both balls are accelerated, and the lower ball is moving fastest.
D) the lower ball is accelerated, but the upper ball is not accelerated.
E) neither ball is accelerated, and the lower ball is moving fastest.
Answer: E
16) Is it possible for an object to accelerate but without changing its speed?
A) Yes, for example when a car is halfway up a straight hill [a hill whose slope, or angle
with the horizontal, does not change] and moving a an unchanging speed.
B) Yes, for example when a car turns a corner while maintaining an unchanging speed.
C) Both of the above.
D) No, because the word "acceleration" means "speeding up."
E) No, because the word "acceleration" means "a change in speed."
Answer: B
17) While a stone is falling [neglecting air resistance],
A) the direction of its velocity is downward.
B) its speed is changing.
C) it is accelerated.
D) All of the above.
E) None of the above.
Answer: D
18) Which statement is the most accurate for falling objects on Earth?
A) Heavy objects fall significantly faster than light objects.
B) Neglecting the effects of air resistance, heavy objects fall faster than light objects.
C) Neglecting the effects of air resistance, light objects fall faster than heavy objects.
D) All objects fall at roughly the same speed.
E) Neglecting the effects of air resistance, all objects fall at roughly the same speed.
Answer: E
19) On the planet Venus, a Venusian picks up a stone and drops it into a deep hole. If it falls 3 m
in 1 second, how far will it fall in 2 seconds? You can neglect Venusian air resistance.
A) 6 m
B) 9 m
C) 12 m
D) 15 m
E) 20 m
Answer: C
20) An astronaut drops a rock on the moon. It falls 1 meter in 1 second. In 4 seconds, it falls a
total distance of
A) 4 meters.
B) 8 meters.
C) 9 meters.
D) 12 meters.
E) 16 meters.
Answer: E
21) On Mars, the acceleration due to gravity is 8 m/s/s. If an object is dropped over the surface of
Mars, how fast will it be moving at the end of 3 seconds of fall?
A) 8 m/s
B) 16 m/s
C) 24 m/s
D) 32 m/s
E) 72 m/s
Answer: C
22) On the planet Jupiter, a dropped object picks up a speed of 20 m/sec in one second. How fast
will it be going at the end of 3 seconds of fall, neglecting "air" resistance on Jupiter?
A) 20 m/sec
B) 40 m/sec
C) 60 m/sec
D) 80 m/sec
E) 180 m/sec
Answer: C
23) While a rock is falling straight down with negligible air resistance, it has
A) zero speed.
B) an unchanging speed.
C) a decreasing speed.
D) an increasing speed.
E) None of the above.
A
A
Answer: D
3)
24) The main point of Newton's law of motion is that forces cause
A) velocity.
B) acceleration.
C) energy.
D) All of the above.
E) None of the above.
Answer: B
25) Two single wave pulses are sent along a rope. Both have the same height, but one is upward
and the other is downward. As they are passing through each other, they will momentarily
cancel each other out. What becomes of their energy as they are passing through each other?
A) It is momentarily destroyed due to destructive interference.
B) it is still there in the form of thermal energy of the rope and air.
C) actually the pulses contained no energy to begin with.
D) it is still there in the form of gravitational energy of the rope.
E) It is still there in the form of kinetic energy of the rope.
Answer: E
26) You push your 2 kg physics book along a tabletop, pushing it with 10 newtons of force. The
frictional force on it is 4 newtons. The book's acceleration is
A) 0.2 m/s2.
B) 5 m/s2.
C) 3 m/s2.
D) 2 m/s2.
E) zero.
Answer: C
27) A ball is thrown straight upward. While it is moving upward, the ball's acceleration is
A) zero, i.e. the ball is not accelerating.
B) in the downward direction.
C) in the upward direction.
D) in the horizontal direction.
E) None of the above.
Answer: B
28) If you went to the moon, you would find that
A) it really is made of blue cheese.
B) your weight would be increased.
C) both 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.
Answer: E
29) A book rests on a table, and the table rests on the ground. Which of the following pairs of
forces forms a force pair, or action-reaction pair, obeying Newton's law of force pairs?
A) Gravity pulling down on the book and the table pushing up on the book.
B) Gravity pulling down on the book and the book pushing down on the table.
C) Gravity pulling down on the table and the book pushing down on the table.
D) The ground pushing up on the table and the book pushing down on the table.
E) The table pushing up on the book and the book pushing down on the table.
Answer: E
30)
Mary pushes horizontally on a large, heavy table, which is standing alone in the middle of a
room, and notes that the table does not move despite the fact that she is pushing on it (see
the figure). Why doesn't the table move?
A) The table had so much mass that its inertia kept it from moving.
B) Although it is true that forces cause accelerations, they do not cause velocities;
therefore, the table acquired no velocity.
C) According to Newton's meaning of the word "force," the horizontal push against the
table was not really a force.
D) Frictional forces by the floor on the table legs acted in the opposite direction to produce
a net force of zero.
E) Newton's law of force pairs says that there is an opposite "reaction force" by the table
against the instructor's hand, and this reaction force keeps the table from moving.
Answer:
D
31) An apple weighing 3 newtons hangs, motionless, from a tree branch. The net force on the
apple is
A) impossible to determine from the information that is given.
B) 3 newtons downward.
C) 3 newtons upward.
D) 6 newtons downward.
E) None of the above.
Answer: E
32) One force acting on a falling apple is the apple's weight. Which of the following is the best
description of the other member of the "force pair" [of which the apple's weight is one
member]?
A) Air resistance acting upward on the apple.
B) Gravity pulling downward on the apple.
C) The force of gravity by Earth pulling upward on the apple.
D) The force of gravity by the apple pushing downward on Earth.
E) The force of gravity by the apple pulling upward on Earth.
Answer: E
33) An auto moves at a steady 50 mph down a straight level road. The direction of the force of
air resistance on the car is
A) forward.
B) zero.
C) backward.
D) sideways.
E) downward.
Answer: C
34) An auto moves at a steady 50 mph down a straight level road. Which of the following is the
forward drive force on the auto?
A) The forward push by the engine on the car.
B) The backward push by the drive tires on the road.
C) The drive force is actually zero in this example, because the auto is moving at a
constant speed in a straight line.
D) The backward push by the engine on the car.
E) The forward push by the road on the tires.
Answer: E
35) An auto weighing 3000 newtons has a forward drive force of 1000 newtons. Air resistance on
the car is 100 newtons, and road resistance is 100 newtons. The auto moves along a straight
level road. The net force on this auto is
A) 200 newtons backward.
B) 800 newtons backward.
C) 800 newtons forward.
D) 1000 newtons forward.
E) 1200 newtons forward.
Answer: C
36) Jet planes operate by
A) magic.
B) ejecting ions out the back end of the engine.
C) sucking in air and blowing it rapidly out the back of the engine by means of propeller
blades inside the engine.
D) rocket drive [i.e. ejecting heated rocket fuel rapidly out the back end of the engine].
E) sucking in air, heating it , and allowing it to expand out the back end of the engine.
Answer: E
37) A white dwarf star is about the size of
A) the sun.
B) Earth.
C) a highway truck.
D) the head of a pin.
E) actually, it doesn't have any size at all.
Answer:
B
38) In order to quadruple an object's kinetic energy, we must
A) double its speed.
B) quadruple its speed.
C) double its height
D) quadruple its height.
E) stretch it twice as far.
Answer A
39) Suppose we could magically double the mass of the moon, double the mass of Earth, and
double the distance between Earth and the moon, all at the same time. How would this
affect the force that the moon exerts on Earth?
A) The force would be unchanged.
B) The force would be halved.
C) The force would be doubled.
D) The force would be quadrupled.
E) The force would be multiplied by eight.
Answer: A
40) Mortimer pushes against a wall with a force of 10 newtons for a time of 5 seconds. How
much work does Mortimer do on the wall?
A) none
B) 2 J
C) 5 J
D) 10 J
E) 50 J
Answer:
A
41) The basic physical principal principle that explains the operation of rocket engines is
A) the law of inertia.
B) the law of force pairs.
C) Galileo's principle of falling.
D) the atomic hypothesis.
E) actually, rockets are unexplainable.
Answer: B
42) The principle stating that the work output of a heat engine must be less than its total energy
input is called
A) the law of conservation of energy.
B) the kinetic principle.
C) the first law of thermodynamics.
D) the second law of thermodynamics.
E) Nonsense--there is no such physical law.
Answer:
D
43) Under what condition can a force act on an object and yet do no work on that object?
A) If the object moves with no acceleration.
B) If the object does not move.
C) If the net force on the object is zero.
D) If the force operates at constant (unchanging) power.
E) Nonsense--any force on an object must do work on that object.
Answer: B
44) Which of the following has the effect of reducing the gravitational force between two
objects?
A) Moving the two objects closer together.
B) Increasing the mass of either one of the objects.
C) Both of the above.
D) Moving the two objects farther apart.
E) None of the above.
Answer:D
45) A neutral atom loses one of its electrons. It is then
A) a positive ion.
B) a negative ion.
C) either a negative or positive ion, depending on which electron was lost.
D) a neutral ion.
E) ashamed of itself.
Answer: A
46) If two electrons are at rest a short distance apart, they will feel
A) no electromagnetic forces.
B) a repulsive electric force, but no magnetic force.
C) an attractive electric force, but no magnetic force.
D) both electric and magnetic forces.
E) a magnetic force but no electric force.
Answer:
B
47) A changing magnetic field creates an electric field. This is one way of stating
A) the law of force pairs.
B) the principle of conservation of electromagnetic fields.
C) the electric force law.
D) the magnetic force law.
E) Faraday's law.
Answer: E
48) For light waves, different frequencies mean different
A) brightness.
B) colors.
C) amplitudes.
D) speeds.
E) None of the above.
Answer: B
49) The speed of light is
A) 3 km/s.
B) 300 km/s.
C) 3,000 km/s.
D) 3 million km/s.
E) None of the above.
Answer: E
50) Gamma rays are
A) made up of electrons.
B) made up of helium nuclei.
C) rays of light.
D) a form of electromagnetic radiation.
E) a form of beta radiation.
Answer: D
51) The type of energy that a swinging pendulum has at the high point of its swing is
A) elastic.
B) kinetic.
C) thermal.
D) gravitational.
E) spiritual.
Answer: D
52) The main limitation on the efficiency of heat engines is due to
A) reaction forces due to Newton's third law.
B) friction in the moving parts.
C) the first law of thermodynamics.
D) the second law of thermodynamics.
E) environmental extremists.
Answer: D
53) One difference between moving charges and stationary charges is that
A) moving charges exert both electric and magnetic forces, while stationary charges exert
only electric forces.
B) moving charges exert only magnetic forces, while stationary charges exert both electric
and magnetic forces.
C) moving charges exert only magnetic forces, while stationary charges exert only electric
forces.
D) moving charges exert both electric and magnetic forces, while stationary charges exert
neither electric nor magnetic forces.
E) moving charges stay slender, while stationary charges are couch potatoes.
Answer: A
54) Two electromagnetic have different frequencies but equal amplitudes. The one with higher
frequency has the
A) greater speed.
B) shorter wavelength.
C) lower energy.
D) All of the above.
E) None of the above.
Answer: B
55) Higher energy photons have
A) longer wavelengths.
B) greater speed.
C) higher frequency.
D) All of the above.
E) None of the above.
Answer: C
56) Which part of the electromagnetic spectrum has the lowest frequency?
A) gamma
B) radio
C) ultraviolet
D) infrared
E) visible
Answer: B
57) Would it be easier [i.e. would it require less rocket fuel] to lift a rocket off the moon's surface
or off Earth's surface, and why?
A) It would be equally difficult, because the rocket's mass would be the same on the moon
as on Earth.
B) It would be equally difficult, because the rocket's weight would be the same on the
moon as on Earth.
C) It would be easier on the moon, because the rocket's mass would be less on the moon
than it is on Earth.
D) It would be easier on the moon, because the rocket's weight would be less on the moon
than it is on Earth.
E) It would be impossible for the rocket to lift off of the moon, because there is no air on
the moon.
Answer: D
58) The "drive force" that pushes a car forward is
A) the push of the drive tires against the road.
B) the push of the road against the drive tires.
C) the force of the engine turning the drive tires.
D) the force of the expanding gases inside the engine.
E) unknown to science.
Answer: B
59) The figure shows the moon orbiting around Earth. Suppose that the direction of the moon's
motion is counter-clockwise. Is any net force exerted on the moon?
A) Yes, in the direction of arrow A.
B) Yes, in the direction of arrow B.
C) Yes, in the direction of arrow C.
D) No, because no net force is needed to keep an object moving.
E) No, because the individual forces acting on the moon all balance out to yield a net force
of zero.
Answer: C
60) The wire in Figure carries a current I that is increasing with time at a constant rate. The
induced emf in each of the loops is such that
A) no emf is induced in any loop.
B) all loops experience counterclockwise emf.
C) loop A has clockwise emf, loop B has no induced emf, and loop C has counterclockwise emf.
D) loop A has counterclockwise emf, loop B has no induced emf, and loop C has clockwise emf.
Answer: C
61) What is the current in the 10-Ω resistor ?
+


–
21 V 5 Wˇ 10 Wˇ 5 Wˇ
5 Wˇ
A) 0.60 A
B) 3.0 A
C) 1.2 A
D) 2.4 A
E) 0.30 A
Answer: A
62) What is the equivalent resistance between points a and b when R = 12 W?
A) 20 W
B) 16 W
C) 24 W
D) 28 W
E) 6.0 W
Answer: B
63) The circuit below contains three 100W light bulbs. The emf E = 110 V. Which light bulb(s)
is(are) brightest?
A) A
B) B
C) C
D) B and C
E) All three are equally bright.
Answer: (A)
64) What is the equivalent resistance between points A and B in the figure when R = 10 Ω?
A) 20 Ω
B) 10 Ω
C) 25 Ω
D) 15 Ω
E) 3.2 Ω
Answer: (B)
GOOD LUCK!!!!