If you push twice as hard against a stationary brick wall, the amount of work you do
A) quadruples.
B) doubles.
C) is cut in half.
D) remains constant but non-zero.
E) remains constant at zero.
Sunlight reflected from the surface of a lake
A) is unpolarized.
B) tends to be polarized with its electric field vector parallel to the surface of the lake.
C) has undergone refraction by the surface of the lake.
D) tends to be polarized with its electric field vector perpendicular to the surface of the
lake.
E) is totally polarized.
Consider a container of 2.0 grams of hydrogen (one gram mole). Suppose you removed
all the electrons and moved them to the other side of the Earth (Earth diameter 12740.
Km).
(a) How much charge is left behind?
(b) What is the attractive force between the protons here and the electrons at the other
side of the Earth?
What is the force per meter on a straight wire carrying 5.0 A when it is placed in a
magnetic field of 0.020 T? (The wire makes an angle of 27 with respect to the magnetic
field lines.)
A) 0.26 N/m
B) 0.045 N/m
C) 0.022 N/m
D) 0.17 N/m
E) 0.071 N/m
A 10. kg mass, hung onto a spring, causes the spring to stretch 2.0 cm. The spring
constant is
A) 5.0 N/cm
B) 49 N/cm
C) 0.20 N/cm
D) 20. N/m
E) 0.0020 N/cm
The ultraviolet catastrophe is a catastrophe because
A) human vision cannot detect ultraviolet light directly.
B) Wien’s law predicts an infinite intensity of radiation at small wavelengths.
C) Wien’s law predicts an infinite intensity of radiation at large wavelengths.
D) ultraviolet light will not produce electrons by the photoelectric effect.
Work done by STATIC FRICTION is always
A) along the surface.
B) perpendicular to the surface.
C) positive.
D) negative.
E) zero.
The symbol for a certain isotope of radium is Ra. How many nucleons are there in
the nucleus of this isotope?
A) 88
B) 138
C) 214
D) 226
E) 314
A horizontal wire carries a current straight toward you. From your point of view, the
magnetic field caused by this current
A) points directly away from you.
B) circles the wire in a clockwise direction.
C) points to the left.
D) circles the wire in a counter-clockwise direction.
Kepler’s discovery that T2 /r3 = K applies
A) to orbits where K is a universal constant.
B) only to circular orbits.
C) to lunar motion provided K is the same for planetary motion.
D) to elliptical orbits where r is the average distance.
Two children are riding on a merry-go-round. Child A is at a greater distance from the
axis of rotation than child B. Which child has the larger angular displacement?
A) Child A
B) Child B
C) They have the same zero angular displacement.
D) They have the same non-zero angular displacement.
E) There is not enough information given to answer the question.
0.00325 x 10-8 cm equals
A) 3.25 x 10-12 mm
B) 3.25 x 10-11 mm
C) 3.25 x 10-10 mm
D) 3.25 x 10-9 mm
E) 3.25 x 10-8 mm
Three identical resistors are connected in series to a 12-V battery. What is the voltage
across any one of the resistors?
A) 12 V
B) 3 V
C) 36 V
D) 0 V
E) 4 V
A simple pendulum consists of a mass M attached to a weightless string of length L. For
this system, when undergoing small oscillations
A) the frequency is independent of the length L.
B) the frequency is proportional to the amplitude.
C) the frequency is independent of the mass M.
D) the frequency is proportional to the period.
E) the period is proportional to the amplitude.
Diffusion is described by
A) Boyle’s law.
B) Kepler’s law.
C) Charles’ law.
D) Graham’s law.
E) Archimedes’ law.
Suppose a 70. kg student were to become (be compressed into) a black hole.
(a) What would be his/her Schwarzshild radius (“size” of the B.H.)?
(b) How does this compare to the size of a proton?
Gaussian surfaces A and B enclose the same positive charge +Q. The area of Gaussian
surface A is three times larger than that of Gaussian surface B. The flux of electric field
through Gaussian surface A is
A) nine times larger than the flux of electric field through Gaussian surface B.
B) three times larger than the flux of electric field through Gaussian surface B.
C) equal to the flux of electric field through Gaussian surface B.
D) three times smaller than the flux of electric field through Gaussian surface B.
E) unrelated to the flux of electric field through Gaussian surface B.
The IMAGE of a plane mirror (of a real object) has the following characteristics:
A) virtual, inverted, and magnification > 1
B) virtual, erect, and magnification = 1
C) real, erect, and magnification = 1
D) real, inverted, and magnification < 1
Consider two equal mass cylinders rolling with the same translational velocity. The first
cylinder (radius = R) is hollow and has a moment of inertia about its rotational axis of
M R2, while the second cylinder (radius = r) is solid and has a moment of inertia about
its axis of 0.5 M r2. What is the ratio of the hollow cylinder’s angular momentum to that
of the solid cylinder?
A) r2 to 2R2
B) 2R2 to r2
C) r to 2R
D) 2R to r
E) R to 2r
FIGURE 5-6
The resultant force you exert while pressing a key on the keyboard of your new
computer, for a 1.0-s period, is plotted in Fig. 5-6. How much work did you do during
this 1-s interval?
A) zero
B) 50. J
C) -25. J
D) 12.5 J
E) 22. J
A vertical wire carries a current straight up in a region where the magnetic field vector
points due North. What is the direction of the resulting force on this current?
A) North
B) downward
C) East
D) West
E) South
The path difference for destructive interference is mλ/2 where
A) m = 1, 2, 3, 4, …
B) m = 0, 2, 4, 6, …
C) m = 2, 4, 6 , 8, …
D) m = 0, 1, 2, 3, …
E) m = 1, 3, 5, 7, …
Batter up! Your bat hits the ball pitched to you with a 1500-N instantaneous force. The
ball hits the bat with an instantaneous force, whose magnitude is
A) somewhat less than 1500 N.
B) exactly equal to 1500 N.
C) essentially zero.
D) somewhat greater than 1500 N.
You double your distance from a constant sound source that is radiating equally in all
directions. What happens to the intensity of the sound? It reduces to
A) one-half its original value.
B) one-fourth its original value.
C) one-sixteenth its original value.
D) one-eighth its original value.
E) 1/ of its original value.
A series LRC circuit has a 100-Ω resistor, a 0.100-μF capacitor and a 2.00-mH inductor
connected across a 120-V rms ac voltage source operating at (1000/π) Hz. What is the
resonant frequency of this circuit?
A) 70.7 kHz
B) 17.9 kHz
C) 22.5 kHz
D) 35.3 kHz
E) 11.3 kHz
As the speed of a particle approaches the speed of light, the mass of the particle
A) increases.
B) decreases.
C) remains the same.
D) approaches zero.
E) approaches infinity.
What power lens is needed to correct for nearsightedness where the uncorrected far
point is 75 cm?
A) -1.33 D
B) +1.33 D
C) -0.75 D
D) +0.75 D
E) -1.00 D
A heat engine with an efficiency of 30.0% performs 2500 J of work. How much heat is
discharged to the lower temperature reservoir?
A) 5830 J
B) 8330 J
C) 750 J
D) 1350 J
E) 7080 J
An AC generator rotating at 60. Hertz in a 300. Gauss field has 1000. turns and
produces an rms voltage of 150. volts and an rms current of 70. Amperes.
(a) What is the peak current?
(b) What is the area of each turn in the coil?
The filament in a light bulb has a diameter of 0.050 mm and an emissivity e = 1.0. The
temperature of the filament is 3000°C. How long should the filament be in order to
radiate 60 W of power? The Stefan-Boltzmann constant is 5.67 x 10-8 W/(m2∙K4).
A) 11 cm
B) 9.4 cm
C) 8.6 cm
D) 7.2 cm
E) 5.9 cm
A 30. N stone is dropped from a height of 10. m, and strikes the ground with a velocity
of 13. m/s. What average force of air friction acts on it as it falls?
A) 7.2 N
B) 2.9 N
C) 1.2 N
D) 4.1 N
E) 0.13 KN
A 2.0 μF and a 4.0 μF capacitor are connected in series across an 8.0-V DC source.
What is the charge on the 2.0 μF capacitor?
A) 2.0 μC
B) 4.0 μC
C) 12 μC
D) 11 μC
E) 25 μC
If ℓ = 4, which one of the following is a possible quantum number for n?
A) 0
B) 1
C) 2
D) 4
E) 8
If the ac peak current through a 100 ohm resistor is 1.7 A, the average power dissipated
by the resistance is
A) 85 W.
B) 170 W.
C) 289 W.
D) 220 W.
E) 145 W.
An athlete doing push-ups performs 650 kJ of work and loses 425 kJ of heat. What is
the change in the internal energy of the athlete?
A) -225 kJ
B) -1075 kJ
C) 1075 kJ
D) 225 kJ
E) 276 kJ
If the net force on an object is zero N, does the net torque on the object have to be zero
Nm?
Identify (name) the 12 leptons:
Why won’t a transformer work (stepup or stepdown potential) if a battery is connected
across the input?
An eagle, with a wingspread of 2.0 m, flies due North at 8.0 m/s in a region where the
vertical component of the earth’s magnetic field is 0.2 x 10-4 T. What emf would be
developed between the eagle’s wing tips? (It has been speculated that this phenomenon
could play a role in the navigation of birds, but the effect is too small, in all likelihood.)
A coil of 160 turns and area 0.20 m2 is placed with its axis parallel to a magnetic field
of 0.40 T. The magnetic field changes from 0.40 T in the x-direction to 0.40 T in the
negative x-direction in 2.0 s. If the resistance of the coil is 16 Ω, at what rate is power
generated in the coil?
For the three vectors shown in Fig. 3-6, determine + –.
What distinguishes work done by conservative versus nonconservative forces?
State the underlying physical principle of Gauss’s Law.
“Big Mike” throws a baseball straight up and it eventually falls back to him. When the
ball was at its highest point, what was its velocity and what was its acceleration?
(remember to include magnitude and direction)
Starting from rest, a proton falls through a potential difference of 1.2 kV. What speed
does it acquire?
What are the shortest wavelength X-rays produced by a 50,000-V X-ray tube?
Discuss why it is impossible for a particle to decay into a single particle of less mass.
At what temperature is the average kinetic energy of an atom in helium gas equal to
6.21 x 10-21 J?
A person looks straight down into a large cube of glass. Three cm below the surface is a
bubble. How far below the surface does the bubble appear to the person?
At a rock concert, if the speakers are placed on the floor instead of higher up on a
tower, state if the intensity of the sound you would hear, from the same distance away,
is the same or different and why.
Lisa throws a stone horizontally from the roof edge of a 50. meter high dormitory. It
hits the ground at a point 60. m from the building. Find the time of flight.
Determine the missing reaction product:
1n + 235U = 141Ba + ________ + 3(1n )
A stretched string is observed to have three equal segments in a standing wave driven at
a frequency of 480. Hz. What driving frequency will set up a standing wave with four
equal segments?
State the charge-force law.
The moon has an elliptical orbit around the Earth. The lunar rotational kinetic energy
increases as it comes closer to the Earth and decreases as it moves away. What
mechanism changes the rotational kinetic energy?