The best visible safety light in the darkroom that will emit low-energy photons is
A) violet.
B) blue.
C) green.
D) any of the above
E) none of the above
What is the threshold of hearing?
A) 0.1 decibel
B) 0.01 decibel
C) 1 decibel
D) 10 decibel
E) none of the above
The first law of thermodynamics is a restatement of the conservation of
A) momentum.
B) energy.
C) electric charge.
D) all of the above
E) none of the above
Half-way to the center of a completely hollow planet with a thin uniform shell, your
weight would be
A) one-quarter of your weight on the surface.
B) one-half of your weight on the surface.
C) three-quarters of your weight on the surface.
D) the same as at the surface.
E) zero.
According to Kepler, the speed of a planet is slowest when it is
A) closest to the Sun.
B) farthest from the Sun.
C) neither, for speed is a constant.
A roller-coaster ride with 6 passengers takes 3 minutes. Neglecting friction, a similar
ride with 12 passengers aboard would take
A) 1.5 minutes.
B) 3 minutes.
C) 6 minutes.
D) 18 minutes.
The amount of light from an incandescent lamp that is transmitted through an ideal
Polaroid filter is half, and through a classroom Polaroid filter is
A) less than half.
B) more than half.
C) half.
A liter of hot water will cool to room temperature faster in a
A) black pot.
B) silver pot.
C) red pot.
D) none of the above
The critical angle is least in
A) glass.
B) water.
C) diamond.
D) vacuum.
Two identical freight cars roll without friction (one at 1 m/s, the other at 2 m/s) toward
each other on a level track. They collide, couple together, and roll away in the direction
of
A) the slower car.
B) the faster car.
C) neither, for they stop.
What must you do to get away from the harmful effects of radioactivity?
A) live at the North or South Poles.
B) go deep beneath Earth’s surface.
C) go to the Moon.
D) die.
A setting Sun appears red due to
A) scattering of lower frequencies by larger particles in the air.
B) light’s longer path through air at sunset.
C) lower frequencies of light emitted during sunset.
D) absorption by smaller particles in the air.
The force of gravity does work on a satellite when it is in
A) circular orbit.
B) elliptical orbit.
C) both of these
D) neither of these
Alpha particles are normally repelled by atomic nuclei because
A) their closeness with atomic nuclei violates quantum rules.
B) of oppositely-directed forces.
C) they both have the same sign of electric charge.
D) all of the above
E) none of the above
When a cannon is fired, it recoils as the cannonball is set in motion. The cannon and
cannonball ideally acquire equal
A) but opposite amounts of momentum.
B) amounts of kinetic energy.
C) both of these
D) neither of these
The greater proportion of energy immediately converted to heat rather than light occurs
in
A) a fluorescent lamp.
B) an incandescent lamp.
C) both of these
D) neither of these
The output power of an ideal transformer is
A) greater than the input power.
B) equal to the input power.
C) smaller than the input power.
D) may be any of the above
When you turn on a lamp, the initial current in its filament is greater at first, rather than
a moment later, which indicates
A) something is faulty.
B) a time delay for current attaining its average speed.
C) increased temperature means increased resistance.
D) nothing of interest
In casually observing a cup of tea you are
A) affecting its temperature.
B) affecting its location.
C) both of these
D) neither of these
An excited hydrogen atom is capable of emitting radiation of
A) a single frequency.
B) three frequencies.
C) many more than three frequencies.
A shoe on an inclined surface barely remains at rest when friction equals the
A) weight mg of the shoe.
B) component of mg perpendicular to the surface.
C) component of mg parallel to the surface.
D) none of the above
An object released from rest on another planet requires one second to fall a distance of
6 meters. What is the acceleration due to gravity on this planet?
A) 3 m/s2
B) 6 m/s2
C) 12 m/s2
D) 15 m/s2
E) none of the above
What does a breeder reactor “breed?”
A) more energy output than energy input
B) fissionable isotopes from a non-fissionable isotopes
C) more mass than it begins with
D) all of the above
E) none of the above
When heat is added to boiling water, its temperature
A) increases.
B) decreases.
C) remains unchanged.
D) none of the above
Earth pulls on the Moon, and the Moon pulls on Earth, which tells us that
A) these two pulls comprise an action-reaction pair.
B) both Earth and Moon circle a common point.
C) more massive objects pull harder.
D) all of the above
The energy of a photon is related to
A) the energy given to the atom that emits it.
B) the energy transition in de-excitation.
C) its frequency.
D) all of the above
E) none of the above
The solar radiation curve is
A) a dent in the spherical Sun.
B) the path of the Sun as it circles Earth.
C) a plot of Sun’s brightness versus frequency of emission.
D) a plot of sunlight colors versus their frequencies.
E) a plot of light intensity versus temperature of the Sun.
Light travels fastest in
A) warm air.
B) cool air.
C) a vacuum.
Double the frequency of a musical note and you halve its
A) wavelength.
B) speed.
C) amplitude.
D) all of the above
E) none of the above
The center of a long uniform log is raised to shoulder level while the other end is on the
ground. If instead, the end of the log is raised to shoulder level, the work required is
A) half.
B) the same.
C) twice.