Figure V-5
A small railroad car is pulled by a rope as shown in the sketch (top view). The force F
that the rope exerts on the car has a component along the track and another component
perpendicular to the track. Judging from the diagram, the larger of these two
components would be
1) along the track.
2) perpendicular to the track.
These components will be equal if
3) the rope makes an angle of 45 with the track.
4) the rope is pulled in a direction along the track, rather than at an angle to it.
5) they form an action-reaction pair on the car.
6) but they can never really be equal.
When an electron de-excites from the third quantum level to the second, and then to the
ground state, two photons are emitted. The sum of the emitted frequencies equals the
frequency of the single photon that would be emitted if de-excitation were from the
third to
A) the second level.
B) the ground state.
C) any other level.
D) none of the above
If air were a better conductor, at nighttime Earth would be
A) considerably colder.
B) considerably warmer.
C) not appreciably different in temperature.
The explanation for refraction must involve a change in
A) frequency.
B) wavelength.
C) speed.
D) all of the above
E) none of the above
The pressure in a liquid depends on liquid
A) density.
B) depth.
C) both of these
D) neither of these
A golf ball moving forward with 1 unit of momentum strikes and bounces backward off
a heavy bowling ball that is initially at rest and free to move. The bowling ball is set in
motion with a momentum of
A) less than 1 unit.
B) more than 1 unit.
C) 1 unit.
D) not enough information
Pour a liter of water at 40oC into a liter of water at 20oC and the final temperature of
the two becomes
A) less than 30oC.
B) at or about 30oC.
C) more than 30oC.
As two objects moving toward each other due to gravity get closer, the acceleration of
each
A) decreases.
B) remains constant.
C) increases.
Compared to the atoms that make up the body of an elderly person, the atoms that make
up the body of a newborn baby are
A) newer.
B) actually older.
C) the same age.
When you are beneath the surface of water and looking upward, light from above is
seen
A) within a cone of 96o.
B) at angles beyond a cone of 96o.
C) at any angle if the surface is smooth.
Each note on a piano keyboard has its own
A) pitch.
B) loudness.
C) wavelength.
D) amplitude.
E) none of the above
Compared with a neutron bouncing off a carbon nucleus, a neutron bouncing off an iron
nucleus loses
A) less speed.
B) more speed.
C) the same amount of speed.
Which has more skin compared to its body weight?
A) an elephant
B) a mouse
C) both the same
Harry pulls on the end of a spring attached to a wall. The reaction to Harry’s pull on the
spring is
A) the wall pulling oppositely on the spring.
B) the spring pulling on Harry.
C) both the wall and the spring pulling on Harry.
D) none of the above
A mountain that floats on the mantle indicates that the density of the mantle is
A) less than that of the mountain.
B) about the same as that of the mountain.
C) greater than that of the mountain.
D) none of the above
A current-carrying coil of wire is
A) a superconductor.
B) a superconducting magnet.
C) an electromagnet.
D) a magplane in the making.
The addition of salt to water affects its
A) crystal composition.
B) freezing point.
C) viscosity.
D) liquidity.
E) none of the above
An object that completes 100 vibrations in 5 seconds has a period of
A) 0.5 second.
B) 1 second.
C) 2 seconds.
D) none of the above
The size of the pupil of your eye depends on
A) the brightness of light in the room.
B) your mood.
C) both of these
D) neither of these
In choosing between sound waves and radio waves, which has the greater speed?
A) sound wave
B) radio wave
C) both the same
D) need more information
The A in AM radio stands for
A) acceleration.
B) authorized.
C) amplitude.
D) agony.
E) almost.
Materials generally become warmer when light is
A) absorbed by them.
B) reflected by them.
C) transmitted by them.
D) all of the above
E) none of the above
A standing wave is likely produced when
A) two waves overlap.
B) a wave reflects upon itself.
C) the speed of the wave is zero or near zero.
D) the amplitude of a wave exceeds its wavelength.
The Sun is not seen as yellow-green because
A) it is not yellow-green.
B) it is small part of a mixture of other colors in sunlight.
C) its brightness is only slightly greater than the other colors.
D) our vision is not adapted to yellow-green.
The earliest and most influential Greek philosopher was Aristotle, who among many
contributions taught that
A) the four elements are earth, water, air, and fire.
B) all motion is either natural or violent.
C) violent motion requires a sustained push or pull.
D) all of the above
To make taffy apples, a candymaker buys 100 kg of large apples rather than 100 kg of
small apples. That means she will need
A) less taffy.
B) more taffy.
C) the same amount of taffy.
An educated scientific guess is a
A) hypothesis.
B) theory.
C) either of these
D) neither of these
Reverberation is a phenomenon you would be most likely to hear if you sing in
A) the shower.
B) a small drape-covered room.
C) a large drape-covered room.
D) the desert.
Secondary wavelets spread from a wave with
A) reduced speed.
B) an unchanging speed.
C) an increased speed.
D) none of the above
An efficient step-down transformer decreases
A) power.
B) energy.
C) both of these
D) neither of these
What is special about the ratio distance traveled per unit of time?
A) it is constant for light
B) it is relative to a frame of reference
C) distance traveled very much depends on time
Jocko the clown at the top of a tall flagpole has considerable potential energy relative to
the circus net below. After stepping off the pole and neglecting air resistance, his
potential energy when he is half way to the net is
1) the same as at the top,
2) one quarter the amount at the top,
3) one half the amount at the top,
4) more than one-half the amount at the top,
and compared to his kinetic energy when meeting the net, his kinetic energy at the
half-way point is
5) one half.
6) the same as his potential energy at the half-way point.
7) both of these
8) neither of these
Atmospheric pressure is 105 N/m2 at sea level. This means that
1) a column of air 1 square meter in cross section extending up to the top of the
atmosphere weighs 105 N,
2) the weight of one cubic meter of air at sea level is about 105 N,
3) the density of air is 105 N/m3,
and the force of the atmosphere against a surface of one square meter is
4) somewhat less than 105 N.
5) about 105 N.
6) considerably more than 105 N.
For three identical lamps in parallel with a 1.5-volt dry cell, the voltage across the lower
lamp is
1) 1/2 V.
2) 1 V.
3) 1.5 V.
4) 3 V.
If that lamp is disconnected, the other two lamps will
5) glow the same.
6) glow much more brightly.
7) glow much more dimly.
On cold days your bedroom window may get wet on the inside. This is because
1) the air near the glass becomes saturated.
2) a change in phase from gas to liquid occurs.
3) H2O molecules release energy when they liquify on the glass.
4) fast-moving H2O molecules slow down and condense when they encounter the cold
glass.
If the air in the room were colder than the air outside, then quite likely
5) the glass would be even wetter.
6) no wetness would occur.
7) the glass would be wet (or frosty) on the outside surface.
8) none of the above.
A ball is thrown against a wall, bounces off, and is caught. The number of impulses
acting on the ball is
1) one.
2) two.
3) three.
4) none.
The greatest impulse occurs when the ball
5) is thrown.
6) bounces against the wall.
7) is caught.
8) is zero for each.
9) is nonzero, but the same for each case.
You can exert more force on the pedals of a bicycle if you pull up on the handlebars
because
1) your center of gravity can be shifted to a position directly above the pedals,
2) the handlebars, in turn, pull down on you and this force is transmitted to the pedals,
3) rotational inertia is lessened,
4) rotational inertia is increased,
all of which illustrates
5) that equilibrium is center-of-gravity dependent.
6) the law of action and reaction.
7) inertia may be both linear and rotational.
If in the absence of external forces, a rotating ball of hot gas cools and contracts, its rate
of rotation
1) decreases
2) remains essentially the same
3) increases
and its angular momentum
4) decreases.
5) remains essentially the same.
6) increases.
When air rapidly expands, its temperature will
1) decrease,
2) increase,
3) stay the same,
whereas when air is rapidly compressed, its temperature will
4) decrease.
5) increase.
6) stay the same.
Dew on the grass results from
1) fast-moving molecules.
2) evaporation.
3) open-structured water crystals.
4) the pressure of the atmosphere on water vapor.
5) the slowing down of fast-moving water molecules.
As dew forms on the grass, energy is
6) given to the grass by the water vapor.
7) given up by the grass to the water vapor.
Which of the following expands most when temperature is decreased?
1) iron
2) ice water
3) helium
4)All expand the same.
Which of the following contracts most when temperature is decreased?
5) iron
6) ice water
7) helium
8) All contract the same.
A 100-newton sack of potatoes falls from an airplane. As velocity of fall increases, air
resistance also increases, and when air resistance equals 100 N, the acceleration of the
sack is
1) zero
2) 5 m/s2
3) 10 m/s2
4) 100 m/s2
and the velocity of the sack will be
5) 0 m/s.
6) 5 m/s.
7) 10 m/s.
8) 100 m/s.
9) constant.
A cubic meter of lead which weighs 105 N is submerged in water. The buoyant force
acting on it is about
1) the weight of a cubic meter of water, 104 N
2) half the weight of lead, 1/2 x 105 N
3) the weight of lead, 105 N
because
4) the block loses half its apparent weight when suspended in water.
5) the block displaces 105 N of water.
6) the volume of water displaced is one cubic meter.
We can apply the equationFt = change in (mv) to the case of a baseball player striking a
pitched ball. To impart the maximum change in momentum, mv, to the ball, the batter
hits the ball with the greatest force he can muster and he also
1) extends the time of contact as much as possible by “following through.”
2) makes the time of contact as short as possible, thereby increasing the force.
3) none of the above!
In the impulse-momentum equation applied to hitting the ball, the “v” represents
4) the velocity of the bat.
5) the velocity of the ball.
6) a vector quantity.
As a particle is accelerated to relativistic speeds, laboratory measurements of its
momentum show
1) an increase,
2) a decrease,
3) no change,
and measurements of its volume show
4) an increase.
5) a decrease.
6) no change.
A satellite in an elliptical orbit travels at a
1) constant speed
2) variable speed
3) not enough information to say
because
4) the net force acting on it is zero.
5) of the component of gravitational force existing in its direction of motion.
6) it is characteristic of it to do so.
7) again, not enough information is given to say.
The atoms that make up a newborn baby were made
1) in the mother’s womb,
2) from the food that the mother ate,
3) in the ancient stars,
While all atoms heavier than copper were manufactured by processes
4) photosynthesis.
5) atomic fabrication.
6) supernova explosions.
7) radioactivity.
8) none of these.
A vibrating tuning fork causes an identical fork nearby to vibrate. This is called
1) refraction.
2) resonance.
3) beats.
4) reverberation.
For this to occur, both forks must have the same (or multiple)
5) intensities.
6) amplitudes.
7) frequencies.
8) geometries.
9) all of these.
You would have the most quantity of gold if it weighed 1 N on the
1) Moon.
2) Earth.
3) planet Jupiter.
4) would be the same on each.
This is because
5) on the Moon a greater mass of gold is required for the gravitational force to equal 1
N.
6) weight and mass are directly proportional to each other.
7) gravitational force per mass is greatest on the most massive planet.