ASTR-1020guide

pdf

School

Clemson University *

*We aren’t endorsed by this school

Course

1020

Subject

Physics

Date

Dec 6, 2023

Type

pdf

Pages

Uploaded by ChefBook21819

Which of the following is an example in which you are traveling at constant speed, but not at constant velocity? driving around in a circle at exactly 100 km/hr jumping up and down exactly 60 times per minute driving backward at exactly 50 km/hr rolling freely down a hill in a cart, traveling in a straight line none of the above Question 2 If an object's velocity is doubled, its momentum is quadrupled. halved. doubled. dependent on its acceleration. unchanged. Question 3 You are standing on a scale in an elevator and notice that your weight is lower than your normal weight. What do you conclude is occurring? The elevator is accelerating downward. The elevator is moving at a constant velocity upward. The elevator is accelerating upward. Your diet is working. The elevator is moving at a constant velocity downward. Question 4 You observe an object to be moving in a straight line at a constant speed. What can you conclude? (Assume the object does not have any engines or other power source.) No forces of any kind are acting on the object. The only force acting on the object is gravity. Some unseen force must be keeping the object in motion. The only force acting on the object is air resistance. The net force acting on the object is zero.

Question 5 Consider Newton's second law states, often written as force = mass × acceleration. If a known force is applied to an object with a known mass, what does this law predict for the object's acceleration? Correct! acceleration = force / mass acceleration = mass × force acceleration = mass / force Newton's second law is irrelevant for solving this problem. Question 6 1 / 1 pts Which person realized the laws of gravity applied to objects both on Earth and in space? Kepler Copernicus Correct! Newton Galileo Question 7 0 / 1 pts The Earth exerts a gravitational force on a person standing on the surface. The person also exerts a gravitational force on the Earth. Based on Newton's third law of motion, how do these two forces compare? The person exerts a slightly stronger force than the Earth. The Earth exerts a much stronger force than the person. You Answered The Earth exerts a slightly stronger force than the person. The person exerts a much stronger force than the Earth. Correct Answer The forces exerted by the Earth and the person are the same. Question 8 0 / 1 pts Which law explains why a skater can spin faster by pulling his arms closer to his body, or spin slower by spreading his arms out? the law of conservation of energy You Answered the law of conservation of momentum the law of gravity Newton's third law of motion Correct Answer the law of conservation of angular momentum

Question 9 0 / 1 pts How does a rocket take off? Its rocket engines push against the launch pad, propelling the rocket upward. It achieves lift from its wings in the same way that airplanes do. Correct Answer Hot gas shoots out from the back of the rocket and, by conservation of momentum, the rocket moves in the opposite direction. It converts mass-energy to kinetic energy. You Answered The hot rocket exhaust expands the air beneath the rocket, propelling it forward. Question 10 1 / 1 pts In the formula E = mc2, what does E represent? the kinetic energy of a moving object the radiative energy carried by light the gravitational potential energy of an object held above the ground the electric charge of the object Correct! the mass-energy or potential energy stored in an object's mass Question 11 1 / 1 pts The gravitational force between two objects can be described using the equation Fg = G M1 M2 / d2. According to this equation, if the distance between two objects increases, what happens to the gravitational force between them? The force drops instantly to zero. The force increases. Correct! The force decreases. The gravitational force is not affected by distance. Question 12 1 / 1 pts We can see each other in the classroom right now because we emit thermal radiation. reflect infrared light. Correct! reflect visible light. emit visible light. emit infrared light.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Question 13 1 / 1 pts How are wavelength, frequency, and energy related for photons of light? Correct! Longer wavelength means lower frequency and lower energy. Longer wavelength means lower frequency and higher energy. Longer wavelength means higher frequency and lower energy. Longer wavelength means higher frequency and higher energy. There is no simple relationship because different photons travel at different speeds. Question 14 1 / 1 pts From shortest wavelength to longest wavelength, which of the following correctly orders the different regions of electromagnetic radiation? infrared, visible light, ultraviolet, x-rays, gamma rays, radio radio, infrared, visible light, ultraviolet, x-rays, gamma rays visible light, infrared, x-rays, ultraviolet, gamma rays, radio Correct! gamma rays, x-rays, visible light, ultraviolet, infrared, radio radio, x-rays, visible light, ultraviolet, infrared, gamma rays Question 15 0 / 1 pts Why can't we see radio waves? You Answered Radio waves are sound waves, so we hear them. Radio waves have too low energy to be detected by any means. Radio waves fade away before they can reach our eyes. We do see radio waves, but we interpret them as the color red. Correct Answer Radio waves have wavelengths too long for the eye to detect. Question 16 0 / 1 pts An iron atom has an atomic number of 26 and an atomic mass number of 56. If it is neutral, how many protons, neutrons, and electrons does it have? You Answered 26 protons, 30 neutrons, 30 electrons 13 protons, 43 neutrons, 13 electrons Correct Answer 26 protons, 30 neutrons, 26 electrons 13 protons, 56 neutrons, 13 electrons 26 protons, 56 neutrons, 26 electrons

Question 17 1 / 1 pts At extremely high temperatures (e.g., millions of degrees), which of the following best describes the phase of matter? a gas consisting of individual, neutral atoms, but no molecules a plasma consisting of rapidly moving, neutral atoms Correct! a plasma consisting of positively charged ions and free electrons a gas of rapidly moving molecules matter cannot exist at extremely high temperatures. Question 18 0 / 1 pts Which of the following objects does not produce a spectrum that is a close approximation to a thermal radiation spectrum? You Answered you Correct Answer a hot, transparent gas a star a filament in an ordinary (incandescent) light bulb a planet Question 19 1 / 1 pts The diagram above represents energy levels in a hydrogen atom. Each level is labeled with its energy (above the ground state of Level 1) in units of electron/volts (eV). The labeled transitions represent an electron moving between energy levels. Which transition represents an electron that absorbs a photon with 10.2 eV of energy? A Correct! B C D E Question 20 1 / 1 pts What do we mean by the straightest possible path along Earth's surface between two points on Earth's surface? a path that actually is a perfect straight line

a path that follows a circle of longitude Correct! the shortest path between the two points a path that follows a circle of latitude a path that crosses the equator Question 21 1 / 1 pts Alice is floating freely in her spacecraft, and you are accelerating away from her with an acceleration of 1g. Suppose you claim that you are feeling the effects of a gravitational field. How can you explain the fact that Alice is weightless? Correct! She is weightless because she is in free-fall. If you are in a gravitational field, then she cannot be weightless. She is weightless because she is moving at constant velocity. She is weightless because she is in a not moving. Question 22 1 / 1 pts If you draw a spacetime diagram, how will the worldline of an object that is traveling by you at constant speed appear? vertical horizontal Correct! slanted curved a circle Question 23 1 / 1 pts Denver, Colorado and Madrid, Spain are at nearly the same latitude (about 40°N). If you travel from Denver to Madrid staying at the same latitude the entire trip, will you be taking the shortest route? No. The shortest path on the Earth must always be a straight line. Correct! No. The shortest path on the Earth has to be a great circle. Yes. A flat map of Earth shows this path to be straight, and a path that is straight on a map is the shortest path. Yes. Staying at a constant latitude guarantees the shortest path. Question 24 0 / 1 pts Why can't an object return to a point in spacetime that it previously occupied?

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Correct Answer It would require going back in time. It would require deviating from the straightest possible path. You Answered It could be possible, but only if the universe has a spherical geometry. It would require going faster than the speed of light. Question 25 0 / 1 pts Consider this image that appears to show four identical galaxies arranged as a cross. What are we really seeing? You Answered a large galaxy with four central masses that glow brightly a picture taken with a poorly made telescope, so that a single large object appears as four fuzzy dots. Correct Answer four images of a single background galaxy, created by the gravitational lens of a massive foreground galaxy or cluster four galaxies that are nearly identical because they were born at about the same time Question 26 0 / 1 pts Hydrogen atoms have a spectral line with a wavelength of 656 nm. Suppose we observe this particular line from hydrogen gas located near the event horizon of a black hole. Assuming the gas has no motion toward or away from us, where would this line appear in the spectrum? Correct Answer at a wavelength larger than 656 nm You Answered We could not record a spectrum from this gas because its light would be sucked into the black hole and therefore would never reach Earth. at a wavelength shorter than 656 nm at the same wavelength of 656 nm that we observe for this line in the laboratory Question 27 1 / 1 pts The Laser Interferometer Gravitational-Wave Observatory (LIGO) made the first detection of gravitational waves in 2016. Which of the following best describes the discovery? The detection of gravitational waves was a huge surprise because no one had predicted they would exist prior to their discovery. Correct!

The detection verified that gravitational waves exist as predicted by the general theory of relativity. The detection of gravitational waves contradicted predictions made by the general theory of relativity, requiring scientists to revise the theory. There is still considerable doubt whether LIGO really detected gravitational waves. Question 28 1 / 1 pts According to the general theory of relativity, how fast to gravitational waves move through space? the speed of sound the speed of gravity, which is slower than light Correct! the speed of light Gravitational waves can be felt instantaneously over any distance of space. the speed of gravity, which is faster than light Question 29 1 / 1 pts What two forces are balanced in what we call gravitational equilibrium? outward pressure and the strong force the strong force and kinetic energy the strong force and gravity Correct! outward pressure and inward gravity the electromagnetic force and gravity Question 30 1 / 1 pts What keeps the Sun's outer layers from continuing to fall inward in a gravitational collapse? electromagnetic repulsion between protons Correct! outward pressure due to hot gas neutrinos produced by nuclear fusion drag gas outward. the strong force between protons Question 31 1 / 1 pts Which of the following quantities is equal to the energy per second generated by fusion in the Sun's core? the force of gravity holding the Sun together the temperature at the Sun's photosphere

Correct! the luminosity of the Sun's photosphere the temperature of the Sun's core Question 32 1 / 1 pts The Sun's composition (by mass) is approximately 70 percent helium, 28 percent hydrogen, 2 percent other elements. Correct! 70 percent hydrogen, 28 percent helium, 2 percent other elements. 98 percent hydrogen, 2 percent helium, and other elements. 50 percent hydrogen, 25 percent helium, 25 percent other elements. 100 percent hydrogen and helium. Question 33 1 / 1 pts What is the approximate temperature of the Sun's core? 10,000 K 150 million K 1 million K 5800 K Correct! 15 million K Question 34 1 / 1 pts Based on its surface temperature of 5800 K, most photons that leave the Sun's surface lie in the ________ region of the electromagnetic spectrum. x-ray ultraviolet microwave infrared Correct! visible Question 35 0 / 1 pts To estimate the central temperature of the Sun, scientists You Answered create a version of the Sun in a laboratory. Correct Answer use computer models to predict interior conditions. monitor changes in Earth's atmosphere. send probes to measure the temperature.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Question 36 0 / 1 pts Which of the following properties of the Sun tells us the rate at which energy is being generated in its core? Correct Answer luminosity mass surface temperature You Answered apparent brightness Question 37 0 / 1 pts How do today's human-built nuclear power plants on Earth generate energy? nuclear fusion converting kinetic energy into electricity You Answered chemical reactions converting gravitational potential energy into electricity Correct Answer nuclear fission Question 38 1 / 1 pts What temperature is required to fuse hydrogen? thousands of Kelvin billions of Kelvin trillions of Kelvin Correct! millions of Kelvin any temperature, as long as gravity is strong enough Question 39 1 / 1 pts Which is the strongest of the fundamental forces in the universe? weak force electromagnetic force gravitational force Correct! strong force All four forces have the same strength. Question 40

1 / 1 pts About how much mass does the Sun lose through nuclear fusion per second? 4 tons 600 tons Correct! 4 million tons 600 million tons None; mass is conserved. Question 41 1 / 1 pts Suppose you put two protons near each other. Because of the electromagnetic force, what will the two protons do? attract each other Correct! repel each other vollide join together to form a nucleus remain stationary Question 42 1 / 1 pts Which of the following best explains why nuclear fusion requires bringing nuclei extremely close together? Nuclei have to be very hot in order to fuse, and the only way to get them hot is to bring them close together. Correct! Nuclei normally repel because they are all positively charged and can be made to stick only when brought close enough for the strong force to take hold. Nuclei are attracted to each other by the electromagnetic force, but this force is only strong enough to make nuclei stick when they are very close together. Fusion can only proceed by the proton-proton chain and therefore requires that protons come close enough together to be linked up into a chain. Question 43 0 / 1 pts Why does the Sun's rate of fusion gradually rise over billions of years? Correct Answer Fusion reactions decrease the overall number of particles in the core, causing the core to shrink, converting gravitational potential energy into thermal energy, and increasing the rate of fusion. The Sun becomes less efficient and must increase the rate of fusion to produce the same amount of energy.

The radiation produced by fusion reactions that is trapped in the core gradually raises the temperature, increasing the rate of fusion. The rate of fusion is not rising; it is actually decreasing over time. You Answered The Sun gets heavier as it gets older, and the stronger inward pull of gravity increases the fusion rate. Question 44 1 / 1 pts Which of the following statements about neutrinos is not true? Neutrinos have a tendency to pass through just about anything without interactions, making them very difficult to detect. Correct! The mass of a neutrino is 30 percent of the mass of an electron. About a thousand trillion neutrinos are passing through your body every second. Neutrinos have no electrical charge. Neutrinos are created as a by-product of the proton-proton chain. Question 45 0 / 1 pts The solar neutrino problem referred to the fact that, a couple decades ago, fewer neutrinos were being detected from the Sun than predicted by our theory of nuclear fusion. What was the solution to this problem? We learned that our detectors were mistaking neutrinos for the particles known as cosmic rays. Correct Answer We learned that our detectors were detecting only one of three different types of neutrinos that reach us from the Sun. We learned that our detectors were not functioning properly. We learned that the Sun is generating much less energy than we thought it was. You Answered We learned that the Sun is generating energy by means other than nuclear fusion. Question 46 1 / 1 pts When the temperature of the Sun's core goes up, what happens next? Fusion reactions slow down, core shrinks and heats. Fusion reactions slow down, the core expands and heats. Fusion reactions speed up, the core shrinks and cools. Correct! Fusion reactions speed up, core expands and cools. Question 47 0 / 1 pts What would happen in the Sun if the temperature of the core decreased?

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

You Answered The fusion rate increases, then the core shrinks and heats. Correct Answer The fusion rate decreases, then the core shrinks and heats. The fusion rate increases, then the core expands and cools. The fusion rate decreases, then the core expands and heats. Question 48 0 / 1 pts What have studies of sunquakes, or helioseismology, revealed? The Sun vibrates only on the surface. Neutrinos from the solar core reach the solar surface easily. Correct Answer Our mathematical models of the solar interior are fairly accurate. "Sunquakes" are caused by similar processes that create earthquakes on Earth. You Answered The Sun generates energy by nuclear fusion. Question 49 1 / 1 pts This image shows the velocity of gas moving toward or away from us on the Sun's surface, as measured through Doppler shifts; the key indicates the measured velocity, with negative velocities indicating gas moving toward us and positive velocities away from us. Based on this map, about how fast is the sun rotating at its equator? (Hint: determine the speed at which equatorial gas is moving toward us on one side of the equator and away from us on the other.) Correct! about 2000 m/s about 20,000 m/s about 200 m/s The Sun is not rotating. Question 50 1 / 1 pts Which of the following is not a method astronomers use to determine the physical conditions inside the Sun? detecting solar neutrinos generated in the Sun's core building mathematical models that use the laws of physics Correct! observing x-ray images of the solar interior using satellites

measuring Doppler shifts to observe solar vibrations Question 51 0 / 1 pts About a thousand trillion neutrinos are passing through your body every second. Why don't they hurt you? Our immune systems release antibodies that counteract the damage the neutrinos cause. Correct Answer Neutrinos interact with ordinary matter only through the weak force. Actually, they do—neutrinos are the cause of many cancers. You Answered Their masses are too low to cause any damage. They are traveling too slowly to cause any damage. Question 52 0 / 1 pts Why are sunspots cooler than the surrounding solar surface? Magnetic fields trap ionized gases that absorb light. They are regions where convection carries cooler material downward. Magnetic fields lift material from the surface of the Sun, cooling off the material faster. Correct Answer Strong magnetic fields slow convection and prevent hot plasma from entering the region. You Answered There is less fusion occurring there. Question 53 1 / 1 pts The intricate patterns visible in an x-ray image of the Sun generally show structure within sunspots. Correct! extremely hot plasma flowing along magnetic field lines. helioseismological fluctuations. granulation on the photosphere. Question 54 1 / 1 pts Which of the following statements about the sunspot cycle is not true? The number of sunspots peaks approximately every 11 years. The number of solar flares peaks about every 11 years. Correct! The rate of nuclear fusion in the Sun peaks about every 11 years.

The cycle is truly a cycle of magnetic activity, and variations in the number of sunspots are only one manifestation of the cycle. With each subsequent peak in the number of sunspots, the magnetic polarity of the Sun is the reverse of the previous peak. Question 55 1 / 1 pts Based on the above graph, the average time between maximums of the sunspot cycle is about Correct! 11 years. a few months. 110 years. 1 year. Question 56 1 / 1 pts What is a "wormhole"? an observationally confirmed feature of the universe that allows interstellar travel and time travel Correct! a hypothetical connection through hyperspace between two points in the universe another name for the shortest path between two points the opposite of a black hole; it ejects mass and energy out of it and nothing can enter Question 57 1 / 1 pts How many dimensions of space can you move in if you are on the surface of a sphere, and you cannot leave that surface? 1 dimension Correct! 2 dimensions 3 dimensions 4 dimensions Question 58 0 / 1 pts How does the spectrum of a molecule differ from the spectrum of an atom? Correct Answer A molecule has additional spectral lines due to changes in its rotational and vibrational energies. You Answered

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

Molecules only have spectral lines at ultraviolet wavelengths. A molecule does not have spectral lines due to electrons changing energy levels. Most atoms only have spectral lines at infrared wavelengths. An atom has a wider range of spectral lines than molecules. Question 59 0 / 1 pts When an electron in an atom goes from a higher energy level to a lower energy level, the atom may emit a photon of any wavelength. Correct Answer emit a photon of a specific wavelength. absorb a photon of any wavelength. You Answered absorb a photon of a specific wavelength. absorb several photons of a specific wavelength. Question 60 1 / 1 pts Red light has a lower energy per photon than blue light. Therefore, red light has lower frequency, shorter wavelength than blue light. Correct! lower frequency, longer wavelength than blue light. higher frequency, longer wavelength than blue light. higher frequency, shorter wavelength than blue light. Question 61 1 / 1 pts A wave has peaks and troughs that can move matter up and down when the wave interacts with matter. The frequency of a wave is the distance between two adjacent peaks of a wave. the speed at which a wave moves through space. Correct! the number of peaks passing by any point each second. Question 62 0 / 1 pts If a material is transparent, then it reflects light well. You Answered emits light well. absorbs light well. scatters light well. Correct Answer

transmits light well. Question 63 1 / 1 pts Which of the following best describes why Earth has tides? Air pressure from the atmosphere pushes on the surface of the ocean. Correct! Earth gets stretched out because the gravitational force from the Moon is stronger on parts of the Earth that are nearer to the Moon. Earth's sea level changes constantly because of rainfall. Earth gets stretched out because the Moon pulls from one side, while the Sun pulls from the other. Earth bulges near its equator because it is spinning. Question 64 1 / 1 pts Suppose the Sun were to suddenly shrink in size but its mass remained the same. According to the law of conservation of angular momentum, what would happen? The Sun's angular size in our sky would increase. The Sun's rate of rotation would remain the same. Correct! The Sun rate of rotation would increase. The Sun's rate of rotation would slow. Question 65 0 / 1 pts According to the universal law of gravitation, if the masses of both attracting objects double, then the gravitational force between them will You Answered increase by a factor of 2. not change at all. Correct Answer increase by a factor of 4. decrease by a factor of 4. decrease by a factor of 2. Question 66 1 / 1 pts Which of the following statements correctly describes the law of conservation of energy? Correct! Energy can change between many different forms, such as potential, kinetic, and thermal, but the total quantity of energy in the universe never changes. It is not really possible for an object to gain or lose potential energy because energy cannot be destroyed.

An object always has the same amount of energy. The fact that you can fuse hydrogen into helium to produce energy means that helium can be turned into hydrogen to produce energy. Energy can change between many different forms, such as potential, kinetic, and thermal, but it is ultimately destroyed. Question 67 1 / 1 pts What does temperature measure? the average size of particles in a substance the total potential energy of particles in a substance the average mass of particles in a substance Correct! the average kinetic energy of particles in a substance the total number of particles in a substance Question 68 1 / 1 pts Gasoline can be used to power cars because it has Correct! chemical potential energy. kinetic energy. gravitational potential energy. electrical potential energy. radiative energy

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version

Access to all documents
Unlimited textbook solutions
24/7 expert homework help

ASTR-1020guide

Related Documents