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physics
conceptual physical science
Conceptual Physical Science 6th Edition Paul G. Hewitt, John A. Suchocki, Leslie A. Hewitt - Solutions
What keeps a main-sequence star from collapsing?
Why do nuclear fusion reactions not occur on the outer layers of stars?
Why are massive stars generally shorter lived than low-mass stars?
Why are supermassive stars relatively rare?
Why will the Sun not be able to fuse carbon nuclei in its core?
Elements heavier than iron are created in stars. Are they formed in the same way as elements lighter than iron? Explain.
With respect to stellar evolution, what is meant by the statement “The bigger they are, the harder they fall”?
A black hole is no more massive than the star from which it collapsed. Why, then, is gravitation so intense near a black hole?
What happens to the radial distance of the event horizon as more and more mass falls into a black hole? Please explain.
What is the difference between a black hole’s photon sphere and its event horizon.
Will the Sun become a supernova? A black hole? Defend your answer.
Which is more dense: the surface of a neutron star or a black hole’s event horizon?
For a visitor, why would a supermassive black hole be safer than a small one?
Does the Milky Way galaxy contain an active galactic nucleus?
Draw an analogy between a galaxy and a forest.
Draw an analogy between a galaxy and a swarm of mosquitoes.
Compare and contrast astronomy and astrology?
Project what human civilization would be like if our Sun were hidden in a dusty part of the galaxy such that no stars were ever visible to us at night.
What did inflation do to the quantum fluctuations found within the early universe?
It takes an infinite amount of time to watch an object fall through a black hole’s event horizon. In what sense, therefore, can it be said that black hole singularity does not exist?
Why is it important to have a science-based understanding of the structure of our universe? Try condensing your answer into a single philosophical sentence.
What is a Cepheid?
Which depends on distance: a star’s brightness or its luminosity?
What is the approximate age of the universe?
Judging by the cosmic background radiation, what is the average temperature of the universe today?
According to cosmic inflation theory, how long did it take for the universe to increase its size by a factor of 1030?
At what point did the universe’s temperature even out?
How many dimensions are there in spacetime?
In what year did Einstein publish his general theory of relativity?
Can an accelerated frame of reference be distinguished from a gravitational field?
You release a ball while standing on the floor of an accelerating spaceship. What happens to the ball?
What did general relativity predict about the orbit of Mercury?
What happens to starlight as it passes close to the Sun?
Within a spaceship moving at 99% the speed of light, what do you notice about the onboard clocks?
Why is the essence of a coffee table best captured with a video camera, rather than with a still camera?
What type of matter is visible?
If we can’t see dark matter, how do we know it is there?
Is dark matter found mostly within a galaxy or just outside a galaxy?
The closer a planet is to the Sun, the faster it orbits. Is it also true that the closer a star is to the center of the galaxy, the faster it orbits?
In a huge cloud of ordinary matter and dark matter, the two are uniformly mixed together. Over time, the ordinary matter becomes concentrated toward the center of this cloud. Why?
Did Einstein first believe that the universe was static or dynamic?
What did Einstein refer to as the greatest blunder of his life?
According to recent evidence, how long ago did the expansion of the universe start accelerating?
What does WMAP stand for?
What is probably the major constituent of our universe?
Which is more abundant: dark matter or ordinary matter?
According to the heat death scenario, about how long will it take for the black holes of the universe to evaporate?
What does the Big Rip scenario assume about dark energy?
What scenario for the fate of the universe proposes that cosmic inflation is not a one-time event?
Rank the following in order of increasing abundance in the universe:(a) Helium.(b) Hydrogen.(c) Carbon.
Rank the following in order of increasing abundance in the universe:(a) Dark matter.(b) Ordinary matter.(c) Dark energy
Rank the following in order of longest ago to most recent:(a) Star formation.(b) Inflation.(c) Big Bang
Rank the following in order of increasing duration: One minute on the surface of (a) Earth.(b) Mercury.(c) The Moon.
When was most of the helium in the universe created?
What does the expansion of space do to light passing through it?
A police officer pulls you over for speeding. He tells you that his radar tracked you moving at a rate of 45 mph away from his parked police car. Were you really speeding away from him, or was the space between the two of you simply expanding?
If the initial universe had remained hotter for a longer period of time, would there probably be more helium or less helium?
Are astronomers able to point their telescopes in the direction of where the Big Bang occurred?
A helium balloon here on Earth pops, releasing direct remnants of the Big Bang. True or False? Explain.
Astronomers tell us that the average temperature of the universe is a rather homogeneous 2.73 K (+/- 0.0001 K). But how can this be when we know that stars are ultra-hot?
The average temperature of the universe right now is about 2.73 K. Is this temperature likely to go up or down over the next billion years?
What are three lines of evidence supporting cosmic inflation?
What if there were symmetry to cosmic background radiation such that the pattern of temperature fluctuations in one direction was exactly the same as the pattern of temperature fluctuations in the opposite direction? What might you conclude about the curvature of the universe?
Is cosmic inflation a cause or an effect? How about dark energy?
Explain how weight can be caused by both gravity and acceleration.
You toss a tennis ball up and down in front of you as you sit in a jet airplane that is accelerating down the runway for takeoff. Why is the tennis ball difficult to catch?
You toss a tennis ball up and down in front of you as you sit in a jet airplane that is cruising at a constant velocity of 500 miles per hour. Why is the tennis ball easy to catch, despite the fact that the jet is moving so fast?
You are free-floating in a spaceship that is in uniform motion deep in outer space. A ball is hovering in front of you. Suddenly the ball starts moving to the floor. What is happening to the spaceship? What happens to you?
Where does a clock run slower: at the front end or the back end of an accelerating spaceship?
Several billion years in the future, our Sun will grow in size to become a red giant, whose surface will extend to the present orbit of Earth. After this happens, will the slowing of time on the Sun’s surface be more or less pronounced than it is today?
Being ultra-sensitive, should a person who wants to live a long life live at the top or at the bottom of a tall apartment building?
A man leaves his identical twin brother behind to live on another planet that is half as massive. After living apart for many years, the two brothers are reunited on the original planet. According to general relativity, which of the two brothers is now younger than the other? Please explain.
When do clocks move slowest on Mercury?
Assume the onboard light in Figure 28.18 is fixed to the back wall. For whom does this light hit the front wall first: the onboard observer or the observer at rest on a planet as shown in Figure 28.19?
Assume the onboard light in Figure 28.18 is fixed to the front wall. For whom does this light hit the back wall first: the onboard observer or the observer at rest on a planet as shown in Figure 28.19? Figure 28.18Figure 28.19 FIGURE 28.18
Astronomers view light coming from distant galaxies that are receding from us at very high speeds, greater than 10% of the speed of light (that is, at about 30,000 km/s). How fast does this light meet the telescopes of the astronomers?
Inside the moving compartment of Figure 28.18, light travels a certain distance to the front end and a certain distance to the back end of the compartment. How do these distances compare as seen in the frame of reference of the moving rocket?
How do the distances in Exercise 73 compare as seen in the frame of reference of an observer on a stationary planet (Figure 28.19)?
If we are made of stardust, what are stars made of?
What might we assume about the distribution of dark matter if the planets in our solar system all orbited the Sun at about the same speed?
Early astronomers such as Kepler and Newton developed the laws of gravity on the basis of the motion of the planets around the Sun. How might these laws be different if our solar system were set within a thick halo of dark matter?
What force allows dark matter to clump?
Why doesn’t dark matter clump together as effectively as ordinary matter?
If dark matter is affected by gravity, might there be lots of it surrounding us here on the surface of Earth?
What is the relationship between dark energy and Einstein’s cosmological constant?
Is space just the absence of matter?
What is one important difference between dark matter and dark energy?
Why is dark energy not called the dark force?
If the universe were unchanging and there were an infinite number of stars, what effect might this have on the darkness of a clear night sky?
The y-axis in the largest graph of Figure 28.27 is given in units of “redshift, z.” How is this related to velocity, as given in the y-axis of the smaller graph above it? Original Hubble data 50 100 Distance (Mpc) Slight curve Downward .01 Distance (Mpc) п T 10000 1000 100 000S Velocity
Mass can transform into energy, and energy can transform into mass, in accordance with Einstein’s equation E = mc2. If the amount of mass–energy in the universe remains constant, what happens to the amount of space within the universe? What, then, is happening to the density of the universe?
If there are so many stars and galaxies, why do we see so much darkness in the clear night sky?
If we can’t even predict the weather, how can we ever expect to predict the fate of the universe?
Compare and contrast the Big Bang and a black hole?
Describe the connection between special and general relativity
For every question we can answer with our space telescopes, there are more questions that arise. Why, then, should we continue looking for answers?
What are the BrØnsted–Lowry definitions of acid and base?
When an acid is dissolved in water, what ion does the water form?
When a chemical loses a hydrogen ion, is it behaving as an acid or a base?
What does it mean to say that an acid is strong in aqueous solution?
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