Physics Final Flashcards
a light year equals what distance?
9.46 x 10 ^12 km or 5.88 x 10^12 miles
what event began the universe
the big bang
a constellation’s changing position in the sky, at the same time of the evening, over a period of several weeks is evidence that..
earth revolves around the sun
the telescope that solved the problem of color separation was the…
reflecting telescope
the Coriolis effect provides evidence that…
earth rotates on an axis
which telescope detects invisible electromagnetic radiation?
radio telescope
the period between successive full moons is
29.5 days, lunar month
each of earth’s standard time zones covers about how many degrees
15*c
a benefit that 20th and 21st century space programs have brought to an area outside of astronomy is…
weather, satellites in orbit provide information about weather all over Earth
the right combination of temperature, water, and oxygen
support life on earth
kepler’s first law states that planets orbit the sun in paths called
ellipse
young earth formed a core, mantle, and crust in a process called
differentiation
early fresh water oceans became salty when
rainwater carried dissolved solid rock to the oceans
the two inner planets most alike in size, mass, and density are…
Venus and earth
kepler’s third law describes the relationship between the average distance of a planet from the sun and the planet’s
orbital period
which planet has volcanic regions that may still be active?
mars
kepler’s second law states that equal areas are covered in equal amounts of time as an object
orbits the sun
which of the following planets has the most complex ring system
Saturn
the early atmosphere developed when many volcanic eruptions released large amounts of gases in a process called
outgassing
tide on earth are caused by
moon’s gravitational force
when a meteoroid hits earth, is is called a
meteorite
the idea that the moon’s development began when a large object collided with Earth is called the…
giant impact hypothesis
the moon today looks as it did 3 billion years ago because
the moon cooled more than 3 billion years ago
characteristics of the galilean moons
Io has active volcanoes
Europa is covered by an ice sheet
Callisto is densely cratered
differentiate between the oort cloud and the kuiper belt
kuiper belt is a disk shaped area visible outside saturn’s orbit, and made up of rocky asteroids.
oort cloud is a ring of dust and comets that circles the sun far beyond Pluto and made up of icy comets
how long is the average sunspot cycle
11 years
what is the hottest layer of the sun’s atmosphere called
the corona
energy is the result of
nuclear fusion
the temperature of the sun’s core is approximately
15,000,000*C
what elements make up most of the sun’s mass?
hydrogen and helium
what is a part of the sun’s atmosphere
photosphere and chromosphere
particles thrown off the sun’s corona that can affect Earth’s magnetic field are called
a coronal mass ejection
einstein’s equation E=mc^2 helps scientists understand the sun’s energy because the equation
explains how mass can be converted into huge amounts of energy
the most common element in most stars is
Hydrogen
stars appear to move in circular paths through the sky because
earth rotates on its axis
a nebula begins the process of becoming a protostar when the nebula
develops a redshift
the brightest star in the night sky is
Sirius
a main sequence star generates energy by fusing
hydrogen into helium
the heaviest element formed in the core of a star is
iron
the change in position of a nearby star as seen from different points on Earth’s orbit compared with the position of a faraway star is called
parallax
what do scientists think will happen to the sun in the next 5 billion years
the sun will enter the red giant stage, gorwing and engulfing Mercury, Venus, and Earth
if the spectrum of a star indicates that the star shines with red light, what is the approximate surface temperature of the star
less than 3500*C
explains why an old main-sequence star is made of a higher percentage of helium than a young main sequence star
the old main sequence star will have burned through its hydrogen, producing larger amounts of helium in the process. A young main sequence star is just starting and by starting it generates energy by fusing hydrogen into helium
how does the movement of earth affect the apparent movement of the stars in the sky
The movement of the Earth makes it appear as if the stars are shifting slightly to the west
the milky way galaxy has about 200 billion stars. If only 10% of an estimated 125 billion galaxies thought to exist in the universe were as large as the milky way how many total stars would be in those galaxies
2.5 x 10^21 stars
describe in detail the life cycle of a low/ medium mass star.
The star is born as temperatures increase in a protostar and nuclear fusion occurs. Gravity increases on the matter within the star and the rate of fusion increases. In the main sequence, the star continues fusing hydrogen into helium. They stay for billions of years. In the third stage (leaving the sequence), fusion occurs in the shell of gas expanding the star. Fusion stops when the star runs out of energy and enters its final stages. As the star’s outer gases drift away, the core heats the gases and they appear as a planetary nebula. Gravity causes the remaining matter to collapse inward, until it can no longer be pressed further and a white dwarf is created
according to einstein’s theory of relativity, what does a massive body do to the space around it?
causes it to curve
how do air bags reduce injuries?
they increase the time, there by reducing force
power can be described as
the rate of work done
work unit
joules
what simple machine is found in scissors
lever
a measure of disorder in a system is called
entropy
zero kelvin is how many degrees Celsius
-273 C
example of longitudinal wave
sound
a detected change in the frequency of a sound due to a moving source or a moving observer is
the Doppler effect
loudness of sound depends on
amplitude
pitch of sound depends on
frequency
frequency is measured in
Hz
sound is produced when there are
oscillations in air pressure
rule of nature
scientific law
prefix denoting smallest amount
Nano
hypothesis
prediction
period
amount of time it takes to complete one complete cycle
superconductor
material with zero resistance
series connection
only one path of the current to flow
“electric boy”
Michael faraday
Narrator of the cosmos episode titled “electric boy”
Neil deGrasse Tyson
current is measured in units called
amperes
unit for work and energy
Joule
unit for power
Watt
Six simple machines
wedge, screw, wheel and axle, lever, pulley, and inclined plane
difference of input and output force
input force is the force that you exert on an object. Output force is the force the machine exerts on an object
difference in output and input distance
The input distance is the distance the input force moves the machine. The output distance is the distance the output force is exerted. The output distance has to be greater than the input distance.
difference between kinetic, potential, and thermal energy
Kinetic energy results from the motion of an object. Potential energy is energy of storage due to its position relative to other objects. Thermal energy is the sum of kinetic and potential energy of particles in a system.
Explain the difference between elastic and gravitational potential energy. What is the equation for gravitational PE?
Gravitational PE is the stored energy due to gravity. Elastic PE is stored energy due to the pulled string and bent bow.
GPE = mgh
Why must the biggest hill in a roller coaster be the first hill?
Because friction and drag immediately begin robbing the car of energy
Define entropy
Measure of dispersal energy
Explain the difference between a transverse and a longitudinal wave and give an example of each:
A transverse wave disturbs particles in a medium perpendicular to the direction of the wave travels. For example, vibrations in a guitar string. The disturbance of a longitudinal wave is parallel to the direction of wave travel. For example, a sound wave.
Draw and label parts of a wave graph
Amplitude: distance between the crest and x-axis
Wavelength: the distance between 2 crests
Trough: the minimum of the graph
Crest: the maximum of the graph
What is the equation for wavelength? What is it measured in?
v/f or vt, it is measured in meters
What is frequency measured in?
hertz
What is loudness measured in?
decibels
The speed of a sound wave depends on?
the medium it travels through
The loudness of a sound wave depends on?
amplitude
The pitch of a sound wave depends on?
frequency
What causes sound waves?
a vibrating source
What is the Doppler effect?
The change in frequency of sound caused by the movement of either the source, the detector, or both
Amplitude
the maximum distance the object moves from the equilibrium position
crest
high point on a transverse wave
decibel
unit of measurements for sound level
Doppler effect
the change in frequency of sound caused by either the movement of either the sound, the detector, or both
energy
ability of a system to produce a change in itself or the world around it
frequency
number of complete oscillations
Gravitational PE
stored energy due to gravity
hertz
SI unit of frequency
inclined plane
a sloping surface used for raising heavy bodies
joule
SI unit of work
kinetic energy
energy associated w/ motion
lever
made of a rigid beam and fulcrum
period
the interval of time it takes for a motion to repeat
pitch
the highness or lowness of a sound
power
rate at which energy is transformed / the rate of work done
screw
a twisted inclined plane wrapped around a cylinder in ridges
pulley
mechanisms composed of a wheel and rope used to lift heavy objects onto tall heights
simple machine
any device with little or no moving parts that are used to modify both the motion and magnitude of force applied to an object to perform work
transverse wave
wave that disturbs the particles in the medium perpendicular to the direction of the waves’ travel
watt
1 J of energy transformed in one second
wave
a disturbance that carries energy through matter of space without transferring matter
wavelength
the shortest distance between points where the wave pattern repeats itself
wedge
triangular shaped tool, portable inclined plane, used to separate 2 objects
wheel and axle
a round disk with a rod through the centre of it uses angular momentum and torque to do work on objects
work
a force is applied through a displacement
