Questions Flashcards
What is the most fundamental of physical sciences?
physics
Which metric prefix means million?
mega-
Which metric prefix means thousand?
kilo-
Which metric prefix means hundredth?
centi-
Which metric prefix means thousandth?
milli-
How may base units are there in the SI?
seven
What is a volume of 1000 cm^3 equal to?
1 L
What combination of units expresses density?
mass/length^3
Using significant figures, 49.4 x 59 = ?
2.9 x 10^3 cm²
Equation for average speed?
average speed = (distance traveled)/(time to travel the distance)
v = d/t
Equation for average acceleration?
average acceleration = (change in velocity)/(time for change to occur)
a = (∆v)/(∆t)
Equation for distance of an object dropped?
distance = (1/2)(acceleration due to gravity)(time²) d = 1/2(g)(t²)
Equation for centripetal acceleration?
centripetal acceleration = (speed²)/(radius)
ac = v²/r
What is necessary to designate a position?
a reference point
What is always true about the magnitude of a displacement?
it is less than or equal to the distance traveled
What is true for deceleration?
the acceleration is in the direction opposite to the velocity
What is true for an object in free-fall?
it increases in distance proportionally to t²
If the speed of an object in uniform circular motion is doubled and the radial distance remains constant, then the magnitude of the centripetal acceleration increases by what factor?
4
What is true for a ball thrown at an angle θ to the horizontal?
it has a constant velocity in the x direction, -y direction, and a changing velocity in the +y direction
For a constant linear acceleration, what changes uniformly?
velocity
A projectile launched a t an angle of 28 above the horizontal will have the same range as a projectile launched at what angle?
62 degrees
Equation for weight?
weight = mass x acceleration due to gravity w = mg
Equation for force?
force = (a constant x mass1 x mass2)/(separation distance)² F = (Gm1m2)/(r²)
Equation for linear momentum?
linear momentum = mass x velocity
p = mv
Equation for angular momentum?
angular momentum = mass x velocity x object distance from axis of rotation
L = mvr
Equation for torque?
torque = lever arm x force τ = rF
What is the state of an object being acted upon by an unbalanced force?
accelerated
What is a possible state of an object in the absence of a net force?
at rest, constant speed, or zero acceleration
What is necessary for a change in velocity?
an unbalanced force
According to Newton’s second law of motion, when an object is acted upon by a net unbalanced force, what can e said about the acceleration?
it is inversely proportional to the object’s mass
A change in what affects the weight of an object?
acceleration due to gravity (G)
What is true of the force pair of Newton’s third law?
the two forces act on different objects
What is true about the acceleration due to gravity?
it decreases with increasing altitude
What is true about the constant G?
it is a very small quantity
A child’s toy floats in a swimming pool. The buoyant force exerted on the toy depends on the volume of what?
the water displaced
If a submerged object displaces an amount of liquid with a weight less than its own, when the object is released it will…?
sink
A change in linear momentum requires…?
a change in velocity, an unbalanced force, and an acceleration
Angular momentum is conserved in the absence of…?
a net torque
Equation for kinetic energy?
kinetic energy = 1/2 x mass x velocity²
Ek = 1/2mv²
Equation for work?
work = weight x height W = mgh
Equation for power?
power = (force x distance)/(time) P = Fd/t
Equation for speed of a falling object?
v = √2g∆h
In addition to force, what does work involve?
motion
What is a unit of work?
N x m
What is the SI unit of energy?
joule
What is an example of an object with great kinetic energy?
an object with a mass of 2m and a velocity of 3v
When negative work is done on a moving object, its kinetic energy…?
decreases
Gravitational potential energy depends on what?
mass, acceleration due to gravity, and height
When the height of an object is changed, the gravitational potential energy…?
depends on the reference point
Energy cannot be…?
created
Power is expressed with what units?
J/s
In the U.S., which sectors consumes the most energy?
industry
What would not be classified as a total alternative fuel source?
gasohol
Equation for frequency?
f = 1/period
Equation for wave speed?
wave speed = (wavelength)/(period)
v = λ/T
What is the number of wave cycles for a given period of time called?
frequency
If a ribbon were tied to a stretched string carrying a transverse wave, how would the ribbon be observed to oscillate?
perpendicular to the wave direction
The energy of a wave is related to the square of what?
amplitude
How fast do electromagnetic waves travel in a vacuum?
3.00 x 10^8 m/s
Name the parts of the electromagnetic spectrum from low frequency to high frequency?
radio waves, microwaves, infrared, visible, ultraviolet, x-rays, gamma rays
Sound waves propagate in what?
solids, liquids, and gases
What is the lower frequency limit of the audible range of human hearing?
20 Hz
A sound with an intensity level of 30 dB is how many times louder than the threshold of hearing?
1000
A moving observer approaches a stationary sound source. What does the observer hear?
an increase in frequency
What property does not change in the Doppler effect?
speed
If an astronomical light source were moving toward us, what would be observed?
a blueshift
What occurs when a stretched string is shaken at one of its natural frequencies?
standing waves, resonance, and maximum energy transfer
Equation for focal length of a spherical mirror?
focal length = (radius of curvature for the spherical mirror)/2
f = R/2
What can be said about the angles of incidence and reflection?
they are measured from a line perpendicular to the reflecting surface
To what does the law of reflection apply?
regular reflection, diffuse reflection, and specular reflection
What is the case when the angle of refraction is smaller than the angle of incidence?
the first medium is less dense
What is true of dispersion?
it is responsible in part for a rainbow
What is the unit of index of refraction?
none; it is unitless
What is true of a convex mirror?
it forms only virtual images
What is true for a real image?
it is formed by converging light rays
What is true of a concave lens?
a lens that forms virtual images for Do > f
What is true of a virtual image?
it is formed on the object side of a lens
What happens when the polarization directions of two polarizing sheets are at an angle of 90 degrees to each other?
no light gets through
What is true of diffraction?
it occurs best when the slit width is less than the wavelength of a wave
When does total constructive interference occur?
when waves are in phase
What is Planck’s constant?
6.63 x 10^-34 J∙s
Equation for energy?
energy = Planck's constant x frequency E = hf
Equation for Bohr radius?
Bohr radius = 0.053 x (principal quantum number n)²
r = 0.053n² nm
Equation for electron energy?
electron energy = (-13.60)/(principal quantum number n)²
En = -13.60/n²
Equation for photon energy?
photon energy = energy of initial orbit - energy of final orbit
Planck developed his quantum hypothesis to explain what phenomena?
the ultraviolet catastrophe
Light of what color has the greatest photon energy?
violet
The Bohr theory was developed to explain what phenomena?
line spectra
In what state does a hydrogen electron have its greatest energy?
n = 5
Bombarding a metal anode with high-energy electrons produces what?
microwaves
The amplification of light in a laser depends on what?
stimulated emission
Equation for distance in parsecs?
distance in parsecs = 1/parallax angle in arc seconds
What refers to the celestial sphere?
north celestial pole, vernal equinox, celestial equator
What is the name of the path on the sky that the sun appears to follow as it moves among the stars?
the ecliptic
The angular measure in degrees north or south of the celestial equator is called…?
declination
Name parts of the sun?
the core, convective zone, coronal hole, corona, filament, prominence, sunspots, chromosphere, photosphere
Why are sunspots darker than the regions of the sun around them?
they are cooler than the surrounding material
Where in the sun does the fusion of hydrogen occur?
only in the core
The part of the sun’s structure that we see in visible light is…?
the photosphere
What force keeps all the stars from flying apart?
gravitational force
Which property depends on how far away a star is from us?
its apparent magnitude
A relatively cool star is what color?
red
After the sun runs out of hydrogen, what will be the next color and size of the sun?
red giant star
The famous Horsehead Nebula is what?
a dark nebula
A white dwarf has about the same diameter as what?
the Earth
What is the fundamental quantity of a star that indicates its ultimate fate?
mass
What event is believed to create elements heavier than iron?
a supernova explosion
Black holes appear black for what reason?
light cannot escape them
The Milky Way is classified as what kind of galaxy?
spiral
How much of the universe appears to be normal ordinary matter?
4%
What key observation led Hubble to conclude that the universe is expanding?
the redshift of light from distant galaxies
What is the cosmic background radiation?
the light-energy remnants of the explosion in which the universe was born
What is true of the solar system?
it is a heliocentric system, it is held together by gravitational forces, and it contains planets classified as terrestrial, Jovian, and dwarf
Which of Kepler’s laws gives the most direct indication of the changes in he orbital speed of a planet?
law of equal areas
Which of Kepler’s laws gives an indication of the semi-major axis?
harmonic law
What planet has retrograde motion?
venus
