A 10-N falling object encounters 10 N of air resistance. The net force on the object is
A) 0 N. B) 4 N. C) 6 N. D) 10 N. E) none of these.
A 1-kg rock that weighs 9.8 N is thrown straight upward at 20 m/s. Neglecting air resistance, the net force that acts on it when it is half way to the top of its path is
A) less than 9.8 N. B) 9.8 N. C) more than 9.8 N.
A ball is thrown upwards. Neglecting air resistance, what initial upward speed does the ball need to remain in the air for a total time of 10 seconds?
A) about 50 m/s B) about 60 m/s C) about 80 m/s D) about 100 m/s E) about 110 m/s
A cello string 0.75 m long has a fundamental frequency of 220 hertz. The speed of a wave on the string is
A) 165 m/s. B) 220 m/s. C) 294 m/s. D) 330 m/s. E) none of these.
A certain radioactive isotope placed near a Geiger counter registers 160 counts per second. Eight hours later, the counter registers 10 counts per second. What is the half life of the isotope?
A) 8 hours B) 6 hours C) 4 hours D) 2 hours E) none of these
A certain transformer doubles input voltage. If the primary coil has 10 A of current, then the current in the secondary coil is
A) 2 A. B) 5 A. C) 10 A. D) 25 A. E) none of these.
A chain reaction grows when the average number of liberated neutrons which go on to cause further fissions is
A) zero. B) less than one. C) one. D) greater than one.
A device that transforms mechanical energy into electrical energy is a
A) generator. B) motor. C) transformer. D) magnet. E) none of these.
A flower pot of mass m falls from rest to the ground below, a distance h. Which statement is correct?
A) The speed of the pot when it hits the ground is proportional to h. B) The KE of the pot when it hits the ground is proportional to h. C) The KE of the pot when it hits the ground does not depend on m. D) The speed of the pot when it hits the ground depends on m. E) None of these is correct.
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.
A heater uses 20 A when used in a 110-V line. If electric power costs 10 cents per kilowatt hour, the cost of running the heater for 10 hours is
A) $0.22. B) $0.55. C) $2.20. D) $5.50. E) none of these.
A heavy block at rest is suspended by a vertical rope. When the block is accelerated upward by the rope, the rope tension
A) increases. B) decreases. C) remains the same.
A horse exerts 500 N of force on a heavy wagon. The wagon pulls back on the horse with an equal force. The wagon still accelerates because
A) these forces are not an action-reaction pair. B) nevertheless there is still an unbalanced force on the wagon. C) the horse pulls on the wagon a brief time before the wagon reacts. D) the wagon does not accelerate because these forces are equal and opposite. E) unlike the horse, it is not alive.
A hydraulic press multiplies a force by 100. This multiplication is done at the expense of
A) energy, which is divided by 100. B) the distance through which the force acts. C) the time through which the force acts, which is multiplied by 100. D) the mechanism providing the force. E) none of these.
A mixture of cyan and yellow pigments appears
A) orange. B) green. C) magenta. D) blue. E) blackish brown.
A negatively charged rod is brought near a metal can that rests on a wood table. You touch the opposite side of the can momentarily with your finger. The can is then
A) positively charged. B) negatively charged. C) uncharged. D) charged the same as it was.
A neon atom has a larger atomic number than a helium atom. At the same temperature and pressure, how does the speed of sound in helium gas compare to the speed of sound in neon gas?
A) greater in neon than in helium B) greater in helium than in neon C) the same in both gases D) depends on the frequency of the sound generated
A nucleon has the least mass in the nucleus of
A) hydrogen. B) iron. C) lead. D) uranium. E) plutonium.
A proton and an electron are placed in an electric field. Which undergoes the greater acceleration?
A) electron B) proton C) both accelerate equally D) neither accelerates
Doubling the thickness (diameter) of a rope will multiply its strength by
A) 1/2. B) 1. C) 2. D) 3. E) 4.
Doubling the linear size of an object multiplies its area by
A) 2 and its volume by 4. B) 4 and its volume by 8. C) 8 and its volume by 16. D) none of these.
Double the frequency of a sound and you halve its
A) wavelength. B) speed. C) amplitude. D) all of these. E) none of these.
Consider plane waves incident upon a barrier with a small opening. After passing through the opening, the waves
A) continue as plane waves. B) fan out. C) converge. D) become polarized. E) all of these.
Consider a steaming aluminum soda-pop can that contains a small amount of boiling water. When it is quickly inverted into a bath of cooler water the can is dramatically crushed by atmospheric pressure. This occurs because the pressure inside the can is rapidly reduced by
A) contact with the relatively cool water. B) sudden slowing of the air and steam molecules inside. C) condensation of steam inside. D) reduced internal energy. E) rapid conduction of heat to the relatively cool water.
Consider a sample of water at 0 degrees C. If the temperature is slightly increased, the volume of the water
A) increases. B) decreases. C) remains the same.
Consider a metal ring with a gap cut in it. When the ring is heated, the gap
A) becomes narrower. B) becomes wider. C) retains its size.
Bullets are fired from an airplane in the forward direction of motion. The momentum of the airplane will be
A) decreased. B) unchanged. C) increased.
Both black and white road surfaces absorb sunlight. At the end of a sunny day the warmer road surface will be
A) the black surface. B) the white surface. C) neither -- there is no difference.
Before ice can form on a lake, all the water in the lake must be cooled to
A) zero degrees C. B) 4 degrees C.
Atmospheric pressure is caused by the
A) density of the atmosphere. B) weight of the atmosphere. C) temperature of the atmosphere. D) effect of the sun's energy on the atmosphere.
Astronomers can tell whether a star is approaching or receding from earth by
A) its temperature. B) its change in temperature. C) its absorption spectra. D) the Doppler effect. E) all of these.
An umbrella tends to move upwards on a windy day principally because
A) air gets trapped under the umbrella, warms, and rises. B) buoyancy increases with increasing wind speed. C) air pressure is reduced over the curved top surface. D) all of these.
An object will normally be a net radiator of energy when its internal energy is
A) more than that of its surroundings. B) less than that of its surroundings. C) neither of these, because internal energy is not temperature.
An iron block is placed in a furnace where it is heated and consequently expands. In the expanded condition, its density
A) is less. B) is the same. C) is more.
An industrial flywheel has a greater rotational inertia when most of its mass is
A) nearest the rim. B) nearest the axis. C) uniformly spread out as in a disk.
An ampere is a unit of electrical
A) pressure. B) current. C) resistance. D) all of these. E) none of these.
Alternating current is normally produced by a
A) battery. B) generator. C) both of these. D) neither of these.
According to the uncertainty principle, the more we know about a particle's momentum, the less we know about its
A) kinetic energy. B) mass C) speed. D) location. E) none of these.
According to Newton, doubling the distance between two interacting objects
A) divides by 2 the gravitational force between them. B) multiplies by 2 the gravitational force between them. C) divides by 4 the gravitational force between them. D) multiplies by 4 the gravitational force between them.
According to Neils Bohr, an electron in an excited state could give off
A) at most a single photon until the atom was excited again. B) several photons in a series of transitions to the ground state. C) a continuous cascade of photons for a high-level transition. D) none of these.
About how many octaves are present between 100 hertz and 1600 hertz?
A) 4 B) 5 C) 6 D) 7 E) 8
A woman on the surface of the Earth has a mass of 50 kilograms and a weight of 490 newtons. If the woman were floating freely inside a space habitat far away from Earth, she would have
A) less weight and more mass. B) less weight and the same mass. C) less weight and less mass. D) more weight and less mass. E) none of these.
A torque acting on an object tends to produce
A) equilibrium. B) rotation. C) linear motion. D) velocity. E) a center of gravity.
A substance can absorb heat energy by the process of
A) conduction. B) convection. C) radiation. D) all of these.
A spring is stretched 10 cm by a suspended 1-kg block. If two such springs side by side are used to suspend the block, so each spring supports half the weight of the block, then each spring will stretch
A) 5 cm. B) 10 cm. C) 20 cm. D) 30 cm. E) none of these.
A sheet of paper can be withdrawn from under a container of milk without toppling it if the paper is jerked quickly. This best demonstrates that
A) the milk carton has no acceleration. B) there is an action-reaction pair of forces. C) gravity tends to hold the milk carton secure. D) the milk carton has inertia. E) none of these.
A rock is thrown upward at 50 degrees with respect to the horizontal. As it rises, its horizontal component of velocity
(neglect air resistance) A) increases. B) remains unchanged. C) decreases.
A river 100 m wide flows due south at 1 m/s. A boat that goes 1 m/s relative to the water is pointed due east as it crosses from the west bank. The boat reaches the east bank
A) due east of where it started. B) 141 m farther south than where it started. C) 100 m farther south than where it started. D) 100 m farther north than where it started.
A ring and a disk, initially at rest, roll down a hill together. The one to reach the bottom first
A) is the ring. B) is the disk. C) depends on the masses. D) depends on the relative rotational inertias. E) both reach the bottom at the same time.
During a single period, the distance traveled by a wave is
A) one-half wavelength. B) one wavelength. C) two wavelengths.
Early Greeks knew (to a fair approximation)
A) the size of the moon. B) the size of the Earth. C) the Earth-moon distance. D) all of the above. E) none of the above.
Electric potential, measured in volts, is the ratio of electric energy to amount of electric
A) current. B) resistance. C) charge. D) voltage. E) none of these.
Electrons are made to flow in a wire when there is
A) an imbalance of charges in the wire. B) more potential energy at one end of the wire than the other. C) a potential difference across its ends.
Evaporation is a cooling process because
A) heat is radiated during the process. B) of conduction and convection. C) the more energetic molecules are able to escape the liquid. D) the temperature of the remaining liquid decreases. E) none of these.
Fissioning helium would yield a net
A) absorption of energy. B) release of energy. C) neither absorption nor release of energy.
For light, a red shift indicates that the light source is moving
A) toward you. B) away from you. C) at right angles to you. D) actually, all of these. E) none of these.
Generally speaking, the larger a nucleus is, the greater its
A) stability. B) instability. C) neither stability nor instability.
How many Joules of energy are in one kilowatt-hour?
A) 1 B) 60 C) 60,000 D) 3.6 million E) none of these
Hydrogen and oxygen molecules in a gas sample have the same temperature. This means the hydrogen molecules, on the average, have the same
A) speed and the same kinetic energy. B) speed, but more kinetic energy. C) speed, but less kinetic energy. D) kinetic energy, but more speed. E) kinetic energy, but less speed.
If a volume of air is warmed, it expands. If a volume of air expands, it
A) warms. B) cools. C) neither warms nor cools.
If an alpha particle and a beta particle have the same energy, which particle will penetrate farther into an object?
A) alpha particle B) beta particle C) They both penetrate the same distance.
If an elephant grows to twice its normal height, its weight will be multiplied by about
A) 2. B) 4. C) 6. D) 8. E) none of these.
If the polar icecaps melted, the resulting water would spread over the entire earth. This new mass distribution would tend to make the length of a day
A) longer. B) shorter. C) stay the same.
If the primary of a transformer were connected to a dc power source, the transformer would have a voltage output
A) at a higher efficiency than with an ac source. B) the same. C) that is also dc. D) only while being connected or disconnected. E) none of these.
If you double the frequency of a vibrating object, its period
A) doubles. B) halves. C) is quartered.
In a mixture of hydrogen gas, oxygen gas, and nitrogen gas, the molecules with the greatest average speed are those of
A) hydrogen. B) oxygen. C) nitrogen D) all will have the same average speed at the same temperature.
In both fission and fusion, mass
A) is created from energy of other forms. B) is changed to the form of kinetic energy. C) remains the same.
In the Bohr model of hydrogen, discrete radii and energy states result when an electron circles the atom in an integral number of
A) wave frequencies. B) de Broglie wavelengths. C) diffraction patterns. D) none of these.
In the double-slit experiment with electrons, the electrons arrive at the screen in a
A) particle-like way with a pattern that is particle-like. B) particle-like way with a pattern that is wave-like. C) wave-like way with a pattern that is particle-like. D) wave-like way with a pattern that is wave-like.
In the photoelectric effect, electrons ejected from bound states in the photosensitive material have
A) less kinetic energy than the absorbed photon's energy. B) more kinetic energy than the absorbed photon's energy. C) kinetic energy equal to the absorbed photon's energy.
In the relationship E = hf for a photon emitted from an atom, the symbol E is used to represent the energy
A) of the emitted photon. B) difference between atomic energy states producing the photon. C) both of these. D) neither of these.
Inhaling helium increases the pitch of your voice. The reason for this is that sound travels
A) slower in helium than in air. B) faster in helium than in air. C) the same speed in helium, but the wavelength is greater.
Inside a freely-falling runaway elevator, your
A) acceleration is zero. B) apparent weight is zero. C) gravitational interaction with the Earth is zero. D) all of these. E) none of these.
It is correct to say that impulse is equal to
A) momentum. B) the change in momentum. C) the force multiplied by the distance the force acts. D) all of these. E) none of these.
It is possible to totally convert a given amount of mechanical energy into heat.
A) True. B) False.
It is possible to wholly convert a given amount of heat energy into mechanical energy.
A) True. B) False.
It takes 6 seconds for a stone to fall to the bottom of a mine shaft. How deep is the shaft?
A) about 60 m B) about 120 m C) about 180 m D) more than 200 m
Light is emitted when an electron
A) is boosted to a higher energy level. B) makes a transition to a lower energy level. C) neither of these.
Light refracts when traveling from air into glass because light
A) has greater intensity in air than in glass. B) has greater intensity in glass than in air. C) has greater frequency in air than in glass. D) has greater frequency in glass than in air. E) travels slower in glass than in air.
The reason that buoyant force acts upward on a submerged object is that
A) it acts in a direction to oppose gravity. B) if it acted downward, nothing would float. C) the weight of fluid displaced reacts with an upward force. D) upward pressure against the bottom is greater than downward pressure against the top of the submerged object.
The quality of a musical note has to do with its
A) loudness. B) frequency. C) harmonics. D) amplitude. E) all of these.
The pressure in a liquid depends on liquid
A) density. B) depth. C) both of these. D) neither of these.
The planet Earth loses heat mainly by
A) conduction. B) convection. C) radiation. D) all of these.
The pendulum with the greatest frequency is the pendulum with the
A) shortest period. B) shortest length. C) both of these. D) neither of these.
The newton is a unit of
A) force. B) mass. C) density. D) inertia.
The moderate temperatures of islands throughout the world has much to do with water's
A) poor conductivity. B) vast supply of internal energy. C) high specific heat. D) high evaporation rate. E) absorption of solar energy.
The lowest temperature possible in nature is
A) 0 degrees C. B) -273 degrees C. C) 4 K.
The ideal efficiency for a heat engine operating between the temperatures of 227 degrees C and 27 degrees C is
A) 20%. B) 25%. C) 40%. D) 88%. E) none of these.
The high temperature of the Earth's interior is due mostly to
A) great internal pressure. B) friction as plates move past one another. C) the Earth's natural heat. D) radioactivity.
The first law of thermodynamics is a restatement of the
A) principle of entropy. B) law of heat addition. C) Carnot cycle. D) conservation of energy. E) none of these.
The electric field around an isolated electron has a certain strength 1 cm from the electron. The electric field strength 2 cm from the electron is
A) half as much. B) the same. C) twice as much. D) four times as much. E) none of these.
The center of mass of a human body is located at a point
A) which is fixed, but different for different people. B) that is always directly behind the belly button. C) that changes as a person bends over. D) none of these.
The brightest color emitted by the sun is
A) red. B) orange. C) yellow-green. D) green-blue. E) violet.
The average speed of a horse that gallops a distance of 10 kilometers in a time of 30 minutes is
A) 10 km/h. B) 20 km/h. C) 30 km/h. D) more than 30 km/h.
The attraction of a person's body toward the Earth is called weight. The reaction to this force is
A) the person's body pushing against the Earth's surface. B) the Earth's surface pushing against the person's body. C) the person's body pulling on the Earth. D) none of these.
The atomic number of an element is the same as the number of its
A) protons. B) neutrons. C) nucleons. D) neither of these.
The atomic mass number of an element is the same as the number of its
A) protons. B) neutrons. C) nucleons. D) none of these.
Systems that are left alone, tend to move toward a state of
A) less entropy. B) more entropy. C) no entropy.
Steam burns are more damaging than burns caused by boiling water because steam
A) gives up additional energy when it condenses. B) has more energy per kilogram than boiling water. C) both of these. D) neither of these.
Sound waves cannot travel in
A) air. B) water. C) steel. D) a vacuum. E) sound can travel in all of these.
Some of a wave's energy dissipates as heat. In time, this will reduce the wave's
A) speed. B) wavelength. C) amplitude. D) frequency. E) period.
Room temperature on the Kelvin scale is about
A) 100 K. B) 200 K. C) 300 K. D) 400 K. E) more than 400 K.
Power is transmitted at high voltages because the corresponding current in the wires is
A) also high to deliver appreciable power to distant places. B) low so that overheating of the wires is minimized. C) both of these. D) neither of these.
Pour a liter of water at 40 degrees C into a liter of water at 20 degrees C and the final temperature of the two becomes
A) less than 30 degrees C. B) at or about 30 degrees C. C) more than 30 degrees C.
Plutonium is not found in any appreciable amounts in natural ore deposits because it
A) is artificially created. B) is chemically inert. C) is a gas at room temperature. D) has a short half life. E) none of these.
Most of the radioactivity we personally encounter comes from
A) fallout from past and present testing of nuclear weapons. B) nuclear power plants. C) medical X rays. D) the natural environment.
Most alpha particles fired at a gold foil pass through undeflected because the
A) electric field is zero inside the gold. B) gold atoms, unlike most other metal atoms, are relatively far apart. C) atoms of gold, like any others, are mostly empty space. D) net charge of the gold atoms is zero. E) none of these.
Metal detectors, like the ones used at airports, are activated by
A) electric fields. B) magnetic fields. C) electromagnetic induction. D) alternating current.
Magnetic domains normally occur in
A) iron. B) copper. C) silver. D) all of these. E) none of these.
The source of electrons in an ordinary electrical circuit is
A) a dry cell, wet cell or battery. B) the back emf of motors. C) the power station generator. D) the electrical conductor itself. E) none of these.
The spacings between double-slit interference fringes is increased if the slits are
A) closer together. B) farther apart. C) narrower. D) wider. E) none of these.
The weight of matter comes mostly from its
A) protons. B) electrons.
The white light emitted by a fluorescent lamp is provided by the
A) mercury vapor in the lamp. B) phosphors on the inner surface of the lamp. C) high temperature of the glowing gas. D) filtering effect of the glass tubing.
There is a greater proportion of carbon 14 in
A) new bones. B) old bones. C) same in each.
To say that electric charge is conserved is to say that electric charge
A) may occur in an infinite variety of quantities. B) is a whole number multiple of the charge of one electron. C) will interact with neighboring electric charges. D) can be neither created nor destroyed.
Two 5000-kg freight cars roll toward each other (one at 1 m/s, the other at 2 m/s) on a level track. Thus before they collide one car's kinetic energy is 2500 J and the other's is 10,000 J. After they collide (and couple together) their total kinetic energy is
A) 1250 J. B) 2500 J. C) 7500 J. D) 10,000 J. E) 12,500 J.
Two equal sized buckets are filled to the top with water. One of the buckets has a piece of wood floating in it, making its total weight A) less than the weight of the other bucket. B) equal to the weight of the other bucket. C) more than the weight of the other bucket.
Two identical blocks of iron, one at 10 degrees C and the other at 20 degrees C, are put in contact. Suppose the cooler block cools to 5 degrees C and the warmer block warms to 25 degrees C. This would violate the
A) 1st law of thermodynamics. B) 2nd law of thermodynamics. C) both of these. D) neither of these.
Two identical gliders slide toward each other on an air track. One moves at 1 m/s and the other at 2 m/s. They collide and stick. The combined mass moves at
A) 1/2 m/s. B) 1/3 m/s. C) 1/6 m/s. D) 3/4 m/s. E) 1.5 m/s.
Two objects, A and B, have the same size and shape, but A is twice as heavy as B. When they are dropped simultaneously from a tower, they reach the ground at the same time, but A has a greater
A) speed. B) acceleration. C) momentum. D) all of these. E) none of these.
U-235 and Pu-239 are both
A) radioactive isotopes. B) fissionable isotopes. C) heavier than lead. D) all of these. E) none of these.
Unlike a transverse wave, a longitudinal wave has
A) no amplitude. B) no frequency. C) no wavelength. D) no speed. E) ...a longitudinal wave has all of these.
Using 1000 J of work, a toy elevator is raised from the ground floor to the second floor in 20 seconds. How much power does the elevator use?
A) 20 W B) 50 W C) 100 W D) 1000 W E) 20,000 W
Waves diffract the most when their wavelength is
A) short. B) long. C) both diffract the same.
What is the acceleration of a car that maintains a constant velocity of 100 km/hr for 10 seconds?
A) 0 B) 10 km/hr s C) 10 m/hr s D) 1000 km/hr s
What prevents satellites such as the space shuttle from falling?
A) gravity B) the absence of air drag C) Nothing; they're falling continuously all around the Earth.
When a bimetallic bar made of copper and iron strips is heated, the bar bends toward the iron strip. The reason for this is
A) iron gets hotter before copper. B) copper gets hotter before iron. C) copper expands more than iron. D) iron expands more than copper. E) none of these.
When a nucleus emits a beta particle, its atomic number
A) increases by 1. B) decreases by 1. C) increases by 2. D) decreases by 2. E) none of these.
When a pair of 1-ohm resistors are connected in series, their combined resistance is
A) 1 ohm, and when connected in parallel, 2 ohms. B) 2 ohms, and when in parallel, 1 ohm. C) 1/2 ohm, and when in parallel, 2 ohms. D) 2 ohms, and when in parallel, 1/2 ohm. E) none of these.
When a rock thrown straight upwards gets to the exact top of its path, its
A) velocity is zero and its acceleration is zero. B) velocity is zero and its acceleration is about 10 meters per second per second. C) velocity is about 10 m/s and its acceleration is zero. D) velocity is about 10 m/s and its acceleration is about 10 meters per second per second. E) none of these.
When a twirling ice skater brings her arms inward, her rotational speed
A) increases. B) decreases. C) remains the same.
When a volume of air expands against the environment and no heat enters or leaves, the air temperature will
A) increase. B) decrease. C) remain unchanged.
When an ice cube in a glass of water melts, the water level
A) rises. B) falls. C) remains the same.
When an object is partly or wholly immersed in a liquid, it is buoyed up
A) by a force equal to its own weight. B) by a force equal to the weight of liquid displaced. C) and floats because of Archimedes principle. D) but nevertheless sinks. E) none of these.
When an object is raised above the ground it gains a certain amount of potential energy. If the same object is raised twice as high it gains
A) four times as much potential energy. B) twice as much potential energy. C) neither of these.
When gas in a container is squeezed to half its volume and the temperature remains the same, the gas pressure
A) halves. B) doubles. C) quadruples. D) remains the same.
When the distance between two charges is halved, the electrical force between the charges
A) quadruples. B) doubles. C) halves. D) is reduced by 1/4. E) none of these.
Your weight is
A) actually your mass. B) the gravitational attraction between you and the Earth. C) a property of mechanical equilibrium. D) all of these. E) none of these.
You wish to photograph the image of your little sister, who is standing 2 meters from a plane mirror. Holding the camera beside her head, you should set the distance for
A) 1 meter. B) 2 meters. C) 3 meters. D) 4 meters. E) none of these.
You know that you can safely stand on the overhanging end of a heavy plank that rests on a table. How far out depends on your mass and the mass of the plank. Suppose you can stand on the end of a plank that overhangs the edge of the supporting table 1/4 its total length. Then how massive is the plank compared to your mass?
A) 1/2 your mass B) the same as your mass C) 1 1/2 your mass D) twice your mass E) 4 times your mass
Which radiation has no electric charge associated with it?
A) alpha rays B) beta rays C) gamma rays D) all of these E) none of these
Which of these atoms has the greatest amount of electrical charge in its nucleus?
A) helium B) carbon C) iron D) gold E) uranium
Which of the following is not a vector quantity?
A) velocity B) speed C) acceleration D) None are vector quantities. E) All are vector quantities.
Which of the following is a property of light waves, but not of sound waves?
A) frequency B) wavelength C) amplitude D) polarization E) none of these
Which involves the larger number of calories?
A) the condensation of 1 gram of steam at 100 degrees Celsius to 100 degrees Celsius water B) the change of state of 1 gram of 100-degree-Celsius water to 1 gram of ice at absolute zero C) Both involve the same number of calories.
Which force binds atoms together to form molecules?
A) gravitational B) nuclear C) electrical D) centripetal E) none of these
When work is done by a system and no heat added to it, the temperature of the system
A) increases. B) decreases. C) remains unchanged.
When white light goes from air into water, the color that refracts the most is
A) red. B) orange. C) green. D) violet. E) all refract the same amount.
When we say an appliance "uses up electricity," we really are saying that
A) current disappears. B) electric charges are dissipated. C) the main power supply voltage is lowered. D) electrons are taken out of the circuit and put somewhere else. E) electron kinetic energy is changed into heat.
When water vapor condenses on the inside of a window, the room becomes slightly
A) warmer. B) cooler. C) neither warmer nor cooler.