astro world 2

The video shows a collapsing cloud of interstellar gas, which is held together by the mutual gravitational attraction of all the atoms and molecules that make up the cloud. As the cloud collapses, the overall force of gravity that draws the cloud inward_____because____ .

-gradually becomes stronger -the strength of gravity follows an inverse square law with distance

What is the primary reason that we launch X-ray telescopes into space rather than building them on the ground? 1) X-rays from space do not reach the ground. 2)On the ground, there would be too much light pollution from nearby cities. 3)It is less expensive to launch them into space. 4)Atmospheric turbulence blurs X-ray images too much.

1) X-rays from space do not reach the ground.

According to what we now know from Newton's laws, which of the following best explains why Kepler's second law is true? - Orbits must be elliptical in shape. - This effect happens because of the influence of other planets on a particular planet's orbit. - Gravity is an inverse cube law. - A planet's angular momentum must be conserved as it moves around its orbit.

A planet's angular momentum must be conserved as it moves around its orbit.

An atom of the element iron has an atomic number of 26 and an atomic weight of 56. If it is neutral, how many protons, neutrons, and electrons does it have? A) 26 protons, 30 neutrons, 26 electrons B) 26 protons, 30 neutrons, 30 electrons C) 26 protons, 56 neutrons, 26 electrons D) 13 protons, 43 neutrons, 13 electrons E) 13 protons, 56 neutrons, 13 electrons

A) 26 protons, 30 neutrons, 26 electrons

Electrons orbit an atomic nucleus like planets orbit the Sun. (T/F)

False

Which of the following statements best describes the difference between a refracting telescope and a reflecting telescope? A) A refracting telescope uses a transparent glass lens to focus light while a reflecting telescope uses a mirror to focus light. B) A refracting telescope produces refracted images while a reflecting telescope produces reflected images. C) Reflecting telescopes make much clearer images than can refracting telescopes of the same size. D) It is much easier to make a large refracting telescope than a large reflecting telescope.

A) A refracting telescope uses a transparent glass lens to focus light while a reflecting telescope uses a mirror to focus light.

Which of the following statements about electrons is not true? A) Electrons orbit the nucleus rather like planets orbiting the Sun. B) Within an atom, an electron can have only particular energies. C) Electrons can jump between energy levels in an atom only if they receive or give up an amount of energy equal to the difference in energy between the energy levels. D) An electron has a negative electrical charge. E) Electrons have very little mass compared to protons or neutrons.

A) Electrons orbit the nucleus rather like planets orbiting the Sun.

Which of the following is not an advantage of the Hubble Space Telescope over ground-based telescopes? A) It is closer to the stars. B) Stars do not twinkle when observed from space. C) It can observe infrared and ultraviolet light, as well as visible light. D) It never has to close because of cloudy skies.

A) It is closer to the stars.

What is the purpose of adaptive optics? A) It reduces blurring caused by atmospheric turbulence for telescopes on the ground. B) It allows several small telescopes to work together like a single larger telescope. C) It is a special technology that allows the Hubble Space Telescope to adapt to study many different types of astronomical objects. D) It allows ground-based telescopes to observe ultraviolet light that normally does not penetrate the atmosphere.

A) It reduces blurring caused by atmospheric turbulence for telescopes on the ground.

How are wavelength, frequency, and energy related for photons of light? A) Longer wavelength means lower frequency and lower energy. B) Longer wavelength means higher frequency and lower energy. C) Longer wavelength means higher frequency and higher energy. D) Longer wavelength means lower frequency and higher energy. E) There is no simple relationship because different photons travel at different speeds.

A) Longer wavelength means lower frequency and lower energy.

Which of the following statements about X rays and radio waves is not true? A) Neither X rays nor radio waves can penetrate the earth's atmosphere. B) X rays have shorter wavelengths than radio waves. C) X rays and radio waves are both forms of light, or electromagnetic radiation. D) X rays have higher frequency than radio waves. E) X rays have higher energy than radio waves.

A) Neither X rays nor radio waves can penetrate the earth's atmosphere.

Consider an atom of gold in which the nucleus contains 79 protons and 118 neutrons. What is its atomic number and atomic weight? A) The atomic number is 79, and the atomic weight is 197. B) The atomic number is 79, and the atomic weight is 118. C) The atomic number is 118, and the atomic weight is 197. D) The atomic number is 118, and the atomic weight is 79.

A) The atomic number is 79, and the atomic weight is 197

You observe a distant galaxy. You find that a spectral line normally found in the visible part of the spectrum is shifted toward the infrared. What do you conclude? A) The galaxy is moving away from you. B) The galaxy is moving toward you. C) The galaxy has very weak gravity. D) The galaxy is made purely of hydrogen. E) The composition of the galaxy is changing.

A) The galaxy is moving away from you.

Consider an atom of gold in which the nucleus contains 79 protons and 118 neutrons. If it is doubly ionized, what is the charge of the gold ion and how many electrons remain in the ion? A) The gold ion has a charge of +2 and 77 electrons. B) The gold ion has a charge of +2 and 79 electrons. C) The gold ion has a charge of -2 and 77 electrons. D) The gold ion has a charge of +2 and 2 electrons. E) The gold ion has a charge of +79 and no electrons.

A) The gold ion has a charge of +2 and 77 electrons.

From laboratory measurements, we know that a particular spectral line formed by hydrogen appears at a wavelength of 486.1 nanometers (nm). The spectrum of a particular star shows the same hydrogen line appearing at a wavelength of 485.9 nm. What can we conclude? A) The star is moving toward us. B) The star is moving away from us. C) The star is getting hotter. D) The star is getting colder. E) The "star" actually is a planet.

A) The star is moving toward us.

Which of the following is always true about images captured with X-ray telescopes? A) They are always shown with colors that are not the true colors of the objects that were photographed. B) They always are made with adaptive optics. C) They show us light with extremely long wavelengths compared to the wavelengths of visible light. D) They always have very high angular resolution. E) They are always very pretty.

A) They are always shown with colors that are not the true colors of the objects that were photographed.

When an electron in an atom goes from a higher energy state to a lower energy state, the atom A) emits a photon of a specific frequency. B) absorbs a photon of a specific frequency. C) absorbs several photons of a specific frequency. D) can emit a photon of any frequency. E) can absorb a photon of any frequency.

A) emits a photon of a specific frequency.

higher energy and shorter wavelength than red light. A) higher energy and shorter wavelength than red light. B) higher energy and longer wavelength than red light. C)lower energy and shorter wavelength than red light

A) higher energy and shorter wavelength than red light.

Which of the following objects is not a close approximation of a thermal emitter? A) hot, thin gas B) a star C) a filament in a light bulb D) you E) a planet A) hot, thin gas

A) hot, thin gas

Where should you put a telescope designed for ultraviolet observations? Where should you put a telescope designed for ultraviolet observations? A)in Earth orbit B)on an airplane C)on a high mountaintop

A) in Earth orbit

In what part of the electromagnetic spectrum do the biggest telescopes on Earth operate? A) radio B) infrared C) visible D) ultraviolet E) X-ray

A) radio

Which of the following wavelength regions can be studied with telescopes on the ground? A) radio, visible, and very limited portions of the infrared and ultraviolet regions B) all light with wavelengths longer than ultraviolet wavelengths C) all light with wavelengths shorter than infrared wavelengths D) infrared, visible, and ultraviolet light

A) radio, visible, and very limited portions of the infrared and ultraviolet regions

What celestial coordinate tells you how far east or west a celestial object is in the sky?Part complete A)Right Ascension B)Longitude C)Declination D)Latitiude

A)Right Ascension

Suppose that Mars had a higher surface temperature. How would its spectrum be different? A)The peak in the infrared would be at shorter wavelength. B)It would reflect more of the Sun's blue light. C)It would reflect more of the Sun's red light D)The peak in the infrared would be at longer wavelength.

A)The peak in the infrared would be at shorter wavelength.

Grass appears green because A)it reflects green light and absorbs other colors. B)it emits green light and absorbs other colors. C)it absorbs green light and emits other colors. D)it transmits green light and emits other colors.

A)it reflects green light and absorbs other colors.

Which of the following statements about thermal radiation is always true? A) A hot object emits photons with a longer wavelength than a cool object. B) A hot object emits photons with a higher average energy than a cool object. C) A hot object emits more radio waves than a cool object. D) A hot object emits more X rays than a cool object.

B) A hot object emits photons with a higher average energy than a cool object.

What does the technique of interferometry allow? A) It allows two or more telescopes to obtain a total light-collecting area much larger than the total light- collecting area of the individual telescopes. B) It allows two or more telescopes to obtain the angular resolution of a single telescope much larger than any of the individual telescopes. C) It allows us to determine the chemical composition of stars. D) It allows astronomers to make astronomical observations without interference from light pollution. E) It allows the same telescope to make images with both radio waves and visible light.

B) It allows two or more telescopes to obtain the angular resolution of a single telescope much larger than any of the individual telescopes.

What is meant by spectral resolution? A) It is a measure of how much energy an object emits in different parts of the electromagnetic spectrum. B) It is a measure of how close two spectral lines can be distinguished. C) It is a measure of how close two point sources can be distinguished. D) It is the same as angular resolution when applied to telescopes operating at different wavelengths.

B) It is a measure of how close two spectral lines can be distinguished

How can an electron in an atom lose energy to go from a higher energy level to a lower energy level? A) It loses kinetic energy. B) It releases a photon equal in energy to its own energy drop. C) It absorbs a photon equal in energy to its own energy drop. D) It loses gravitational potential energy. E) It exchanges gravitational potential energy for kinetic energy.

B) It releases a photon equal in energy to its own energy drop.

We can learn a lot about the properties of a star by studying its spectrum. All of the following statements are true except one. Which one? A) The peak of the star's thermal emission tells us its temperature: Hotter stars peak at shorter (bluer) wavelengths. B) The total amount of light in the spectrum tells us the star's radius. C) We can identify chemical elements present in the star by recognizing patterns of spectral lines that correspond to particular chemicals. D) We can look at Doppler shifts of spectral lines to determine the star's speed toward or away from us.

B) The total amount of light in the spectrum tells us the star's radius.

Suppose the angular separation of two stars is smaller than the angular resolution of your eyes. How will the stars appear to your eyes? A) You will not be able to see these two stars at all. B) The two stars will look like a single point of light. C) The two stars will appear to be touching, looking rather like a small dumbbell. D) You will see two distinct stars. E) You will see only the larger of the two stars, not the smaller one.

B) The two stars will look like a single point of light.

The allowed shapes for orbits under the force of gravity are? A) ellipses, spirals, and parabolas. B)ellipses, parabolas, and hyperbolas. C)ellipses and spirals. D)spirals, circles, and squares. E) ellipses only.

B) ellipses, parabolas, and hyperbolas.

Telescopes operating at this wavelength must be cooled to observe faint astronomical objects. A) radio B) extreme infrared C) visible D) X-ray E) gamma-ray

B) extreme infrared

How much greater is the light-collecting area of a 6-meter telescope than a 3-meter telescope? How much greater is the light-collecting area of a 6-meter telescope than a 3-meter telescope? A)two times B)four times C)six times

B) four times

From lowest energy to highest energy, which of the following correctly orders the different categories of electromagnetic radiation? A) infrared, visible light, ultraviolet, X rays, gamma rays, radio B) radio, infrared, visible light, ultraviolet, X rays, gamma rays C) visible light, infrared, X rays, ultraviolet, gamma rays, radio D) gamma rays, X rays, visible light, ultraviolet, infrared, radio E) radio, X rays, visible light, ultraviolet, infrared, gamma rays

B) radio, infrared, visible light, ultraviolet, X rays, gamma rays

Which of the following studies is best suited to a timing experiment? A) studying how different stars differ in their chemical compositions B) studying whether a particular star's brightness is steady or variable C) determining the age of the solar system D) measuring the rotation rate of a distant star E) estimating the time since the Big Bang

B) studying whether a particular star's brightness is steady or variable

What causes stars to twinkle? A) It is intrinsic to the stars—their brightness varies as they expand and contract. B) variations in the absorption of the atmosphere C) variable absorption by interstellar gas along the line of sight to the star D) bending of light rays by turbulent layers in the atmosphere E) the inability of the human eye to see faint objects

B) to eliminate the distorting effects of atmospheric turbulence for telescopes on the ground

Einstein's theory, like Newton's, predicts that, in the absence of air resistance, all objects should fall at the same rate regardless of their masses. Consider the following hypothetical experimental results. Which one would indicate a failure of Einstein's theory? A)Scientists dropping balls from the Leaning Tower of Pisa find that balls of different size but the same mass fall at slightly different rates. B)Scientists dropping balls on the Moon find that balls of different mass fall at slightly different rates. C)Scientists dropping balls from the Leaning Tower of Pisa find that balls of different mass but the same size fall at slightly different rates.

B)Scientists dropping balls on the Moon find that balls of different mass fall at slightly different rates.

Part complete You have found that tides on Earth are determined primarily by the position of the Moon, with the Sun playing only a secondary role. Why does the Moon play a greater role in causing tides than the Sun? A)because the Moon orbits Earth faster than Earth orbits the Sun B)because the gravitational attraction between Earth and the Moon varies more across Earth than does the gravitational attraction between Earth and the Sun C)because the gravitational force between Earth and the Moon is stronger than the gravitational force between Earth and the Sun

B)because the gravitational attraction between Earth and the Moon varies more across Earth than does the gravitational attraction between Earth and the Sun

At which lunar phase(s) are tides least pronounced (e.g., the lowest high tides)? A)new Moon B)both first and third quarters C)both new and full Moons D)first quarter E) full Moon

B)both first and third quarters

When an atom absorbs a photon containing energy, any of the following can happen except which? A) The atom becomes excited. B) The atom is ionized. C) An electron moves from an upper energy level to a lower one. D) An electron moves from a lower energy level to an upper one.

C) An electron moves from an upper energy level to a lower one.

Each of the following describes an "Atom 1" and an "Atom 2." In which case are the two atoms isotopes of each other? A) Atom 1: nucleus with 6 protons and 8 neutrons, surrounded by 6 electrons Atom 2: nucleus with 7 protons and 8 neutrons, surrounded by 7 electrons B) Atom 1: nucleus with 8 protons and 8 neutrons, surrounded by 8 electrons Atom 2: nucleus with 8 protons and 8 neutrons, surrounded by 7 electrons C) Atom 1: nucleus with 92 protons and 143 neutrons, surrounded by 92 electrons Atom 2: nucleus with 92 protons and 146 neutrons, surrounded by 92 electrons D) Atom 1: nucleus with 1 proton and 0 neutrons, surrounded by 1 electron Atom 2: nucleus with 2 protons and 2 neutrons, surrounded by 2 electrons E) Atom 1: nucleus with 4 protons and 5 neutrons, surrounded by 4 electrons Atom 2: nucleus with 5 protons and 5 neutrons, surrounded by 4 electrons

C) Atom 1: nucleus with 92 protons and 143 neutrons, surrounded by 92 electrons Atom 2: nucleus with 92 protons and 146 neutrons, surrounded by 92 electrons

According to the law of universal gravitation, what would happen to Earth if the Sun were somehow replaced by a black hole of the same mass? A) Earth would be quickly sucked into the black hole. B) Earth would slowly spiral in to the black hole. C) Earth's orbit would not change.

C) Earth's orbit would not change.

Oxygen has atomic number 8. How many times must an oxygen atom be ionized to create an O+5 ion, and how many electrons will the ion have? A) It must be ionized three times; it now has five electrons. B) It must be ionized five times; it now has five electrons. C) It must be ionized five times; it now has three electrons. D) It doesn't have to be ionized; it just needs to gain five protons. E) It doesn't have to be ionized; it already has only three electrons.

C) It must be ionized five times; it now has three electrons.

What do astronomers mean by light pollution? A) Light pollution refers to pollution caused by light industry as opposed to heavy industry. B) Light pollution refers to harmful gases emitted by common street lights. C) Light pollution refers to light used for human activities that brightens the sky and hinders astronomical observations. D) Light pollution refers to the lights that must be used inside major observatories and that make it difficult for astronomers' eyes to adapt to darkness. E) Light pollution is another name for sunlight, which makes it impossible to see stars in the daytime.

C) Light pollution refers to light used for human activities that brightens the sky and hinders astronomical observations.

If Earth were twice as far from the Sun, the force of gravity attracting Earth to the Sun would be: A) Twice as strong. B) Half as strong. C) One-quarter as strong.

C) One-quarter as strong.

f one object has a large redshift and another object has a small redshift, what can we conclude about these two objects? A) The one with the large redshift is moving toward us faster than the one with the small redshift. B) The one with the large redshift is moving away from us, and the one with the small redshift is moving toward us. C) The one with the large redshift is moving away from us faster than the one with the small redshift. D) The one with the large redshift is hotter and therefore is putting out more radiation.

C) The one with the large redshift is moving away from us faster than the one with the small redshift.

If you heat a gas so that collisions are continually bumping electrons to higher energy levels, when the electrons fall back to lower energy levels the gas produces A) thermal radiation. B) an absorption line spectrum. C) an emission line spectrum. D) X rays. E) radio waves.

C) an emission line spectrum.

A perfectly opaque object that absorbs all radiation and reemits the absorbed energy as thermal radiation is A) a hot, dense cloud of gas. B) a cold, dense cloud of gas. C) an infrared radiation emitter. D) a thermal emitter. E) transparent.

C) an infrared radiation emitter.

The loss of an electron from a neutral helium atom results in A) neutral hydrogen. B) ionized hydrogen. C) ionized helium. D) neutral deuterium. E) ionized deuterium.

C) ionized helium.

When an atom loses an electron, it becomes A) sublimated. B) dissociated. C) ionized. D) an isotope. E) a plasma.

C) ionized.

The study of energy levels in atoms is called A) special relativity. B) general relativity. C) quantum mechanics. D) classical mechanics. E) particle physics.

C) quantum mechanics.

Thermal radiation is defined as A) radiation produced by a hot object. B) radiation in the infrared part of the spectrum. C) radiation that depends only on the emitting object's temperature. D) radiation in the form of emission lines from an object. E) radiation that is felt as heat.

C) radiation that depends only on the emitting object's temperature.

Consider Earth and the Moon. As you should now realize, the gravitational force that Earth exerts on the Moon is equal and opposite to that which the Moon exerts on Earth. Therefore, according to Newton's second law of motion __________. A)Earth has a larger acceleration than the Moon, because it has a larger mass B)The Moon and Earth both have equal accelerations, because the forces are equal C)The Moon has a larger acceleration than Earth, because it has a smaller mass

C)The Moon has a larger acceleration than Earth, because it has a smaller mass

What does angular resolution measure? A)the number of electromagnetic waves captured by an image B)the brightness of an image C)the angular size of the smallest features that the telescope can see D)the size of an image

C)the angular size of the smallest features that the telescope can see

Which forms of light are lower in energy and frequency than the light that our eyes can see? A) ultraviolet and X ray B) visible light C) infrared and ultraviolet D)infrared and radio

D )infrared and radio

If two objects are the same size but one object is 3 times hotter than the other object, the hotter object emits A) 3 times more energy. B) 9 times more energy. C) 12 times more energy. D) 81 times more energy. E) none of the above

D) 81 times more energy.

Without telescopes or other aid, we can look up and see the Moon in the night sky because it A) emits visible light. B) emits thermal radiation. C) reflects infrared light. D) reflects visible light. E) glows through radioactive decay. D) reflects visible light.

D) reflects visible light.

Which of the following statements about thermal radiation is always true? A) A hot object emits more X rays than a cool object. B) A hot object emits more radio waves than a cool object. C) A hot object emits more total radiation than a cool object. D) A hot object emits more total radiation per unit surface area than a cool object. E) A hot object emits less total radiation than a cool object.

D) A hot object emits more total radiation per unit surface area than a cool object.

Which of the following statements about electrical charge is true? A) Two negative charges will attract each other. B) Two positive charges will attract each other. C) A positive charge and a negative charge will repel each other. D) A positive charge and a negative charge will attract each other.

D) A positive charge and a negative charge will attract each other.

What celestial coordinate tells you how far north or south the celestial object is located in the sky?Part complete A)Rigth Ascension B)Latitude C)Longitude D) Declination

D) Declination

What is meant by the resolution of an optical device?Part complete A)it is the ability of a device to magnify an image of a distant object B)It is the ability of a device to reduce the light pollution which affects the image. C)It is the ability of a device to record the image in a CCD of a distant object. D) It is the ability of an object fo form distinct images of two close objects

D) It is the ability of an object fo form distinct images of two close objects

Suppose you see two stars: a blue star and a red star. Which of the following can you conclude about the two stars? Assume that no Doppler shifts are involved. (Hint: Think about the laws of thermal radiation.) A) The red star is more massive than the blue star. B) The blue star is more massive than the red star. C) The blue star is farther away than the red star. D) The blue star has a hotter surface temperature than the red star. E) The red star has a hotter surface temperature than the blue star.

D) The blue star has a hotter surface temperature than the red star.

You observe the same spectral line in two stars that are identical in every way except that one rotates faster than the other. How does the spectral line differ between the two? A) There is no difference. B) The line in the faster rotating star is blueshifted. C) The line in the faster rotating star is redshifted. D) The line in the faster rotating star is broader. E) The line in the faster rotating star is narrower.

D) The line in the faster rotating star is broader.

If we observe one edge of a planet to be redshifted and the opposite edge to be blueshifted, what can we conclude about the planet? A) The planet is actually two bodies, one moving toward us, the other away from us. B) The planet is in the process of falling apart. C) The planet is in the process of formation. D) The planet is rotating.

D) The planet is rotating.

Which of the following is always true about images captured with X-ray telescopes? A) They are always very pretty. B) They are always displayed with the highest possible angular resolution. C) They are always useful for seeing through things. D) They are always displayed in false color. E) They are always displayed with north pointing upward in the images.

D) They are always displayed in false color.

Choose the correct explanation why does the statement make sense (or is clearly true) or does not make sense (or is clearly false). A) This statement is false. She and the Space Station have different orbits at the beginning but will stay together due to mutual gravity. B) This statement is true. She and the Space Station cannot share the same orbit and will move apart quickly. C) This statement is true. She and the Space Station have different orbits at the beginning and will move apart. D) This statement is false. She and the Space Station share the same orbit and will stay together unless they are pushed apart.

D) This statement is false. She and the Space Station share the same orbit and will stay together unless they are pushed apart.

How much electrical charge does an atom with 6 protons, 6 neutrons, and 5 electrons have? A) a total charge of +17 B) a negative charge of -5 C) a positive charge of +7 D) a positive charge of +1 E) none of the above

D) a positive charge of +1

When white light passes through a cool cloud of gas, we see A) visible light. B) infrared light. C) thermal radiation. D) an absorption line spectrum. E) an emission line spectrum.

D) an absorption line spectrum.

Which of the following wavelength regions cannot be studied with telescopes on the ground? A) radio waves B) ultraviolet C) X rays D) both B and C E) both A and C

D) both B and C

From shortest to longest wavelength, which of the following correctly orders the different categories of electromagnetic radiation? A) infrared, visible light, ultraviolet, X rays, gamma rays, radio B) radio, infrared, visible light, ultraviolet, X rays, gamma rays C) visible light, infrared, X rays, ultraviolet, gamma rays, radio D) gamma rays, X rays, ultraviolet, visible light, infrared, radio E) gamma rays, X rays, visible light, ultraviolet, infrared, radio

D) gamma rays, X rays, ultraviolet, visible light, infrared, radio

According to the universal law of gravitation, if you double the masses of both attracting objects, then the gravitational force between them will A) not change at all. B) increase by a factor of 2. C) decrease by a factor of 2. D) increase by a factor of 4. E) decrease by a factor of 4.

D) increase by a factor of 4.

Red light has a _____ wavelength and a _____ frequency than does blue light. A) shorter, higher B)longer, higher C)shorter, lower D) longer, lower

D) longer, lower

We can see each other in the classroom right now because we A) emit thermal radiation. B) emit visible light. C) emit infrared light. D) reflect visible light. E) reflect infrared light.

D) reflect visible light.

At which lunar phase(s) are tides most pronounced (e.g., the highest high tides)? A)full Moon B)first quarter C)new Moon D)both new and full Moons E)both first and third quarters

D)both new and full Moons

Which of the following statements about X rays and radio waves is not true? A) X rays have shorter wavelengths than radio waves. B) X rays and radio waves are both forms of light, or electromagnetic radiation. C) X rays have higher frequency than radio waves. D) X rays have higher energy than radio waves. E) X rays travel through space faster than radio waves.

E) X rays travel through space faster than radio waves.

Compared to the volume of its nucleus, the volume of an atom is about A) the same. B) a thousand times greater. C) a million times greater. D) a billion times greater. E) a trillion times greater.

E) a trillion times greater.

Which of the following best describes the origin of ocean tides on Earth? A)Tides are caused by the 23 1/2° tilt of the earth's rotational axis to the ecliptic plane. B)Tides are caused primarily by the gravitational force of the Sun. C)Tides are caused on the side of Earth nearest the Moon because the Moon's gravity attracts the water. D)The Moon's gravity pulls harder on water than on land, because water is less dense than rock. E)Tides are caused by the difference in the force of gravity exerted by the Moon across the sphere of the earth.

E)Tides are caused by the difference in the force of gravity exerted by the Moon across the sphere of the earth.

The frequency of a wave is? A)measured in cycles per second. B)equal to the speed of the wave divided by the wavelength of the wave. C)the number of peaks passing by any point each second. D)measured in hertz (Hz). E)all of the above

E)all of the above

The wavelength of a wave is? A)the distance between a peak of the wave and the next trough. B)equal to the speed of the wave times the wave's frequency. C)the distance between where the wave is emitted and where it is absorbed. D)how strong the wave is. E)the distance between two adjacent peaks of the wave.

E)the distance between two adjacent peaks of the wave.

(T/F) Doubling the distance between two objects halves the gravitational force between them.

False

(T/F) There is no gravity in space.

False

(T/F)Process of Science: Gravity only affects very massive objects and we can therefore only test theories about it when looking at the orbits of planets.

False

Atomic nuclei consist of protons and electrons. (T/F)

False

Improvements in technology will eventually allow the entire electromagnetic spectrum to be observed from high mountaintop observatories. Improvements in technology will eventually allow the entire electromagnetic spectrum to be observed from high mountaintop observatories. (T/F)

False

The atomic nuclei of the same element always have the same number of neutrons. (T/F)

False

The greater the wavelength of light, the greater its energy. (T/F)

False

True or false: A radio telescope and an optical telescope of the same size have the same angular resolution

False

(T/F) The centre of mass for Earth orbiting the Sun lies inside the Sun.

True

(T/F)The Moon is constantly falling toward Earth.

True

Lines of a particular element appear at the same wavelength in both emission and absorption line spectra. (T/F)

True

The Moon is slowly moving away from Earth. T/F

True

The atomic nuclei of the same element always have the same number of protons. (T/F)

True

The energy levels for electrons vary from one element to another. (T/F)

True

The shorter the wavelength of light, the higher its frequency. (T/F)

True

X rays from astronomical objects can only be detected from telescopes in space. (T/F)

True

X-rays always have more energy than radio waves. (T/F)

True

You are currently emitting electromagnetic waves. (T/F)

True

According to the universal law of gravitation, the force due to gravity is a) inversely proportional to the square of the distance between objects. b) directly proportional to the square of the distance between objects. c) inversely proportional to the distance between objects. d) not dependent on the distance between objects. e) directly proportional to the distance between objects.

a) inversely proportional to the square of the distance between objects.

The force of gravity is an inverse square law. This means that, if you double the distance between two large masses, the gravitational force between them a) is unaffected. b) weakens by a factor of 2. c) strengthens by a factor of 4. d) also doubles. e) weakens by a factor of 4.

e) weakens by a factor of 4.

The mass of Jupiter can be calculated by A) measuring the orbital period and distance of Jupiter's orbit around the Sun. B) measuring the orbital period and distance of one of Jupiter's moons. C) measuring the orbital speed of one of Jupiter's moons. D) knowing the Sun's mass and measuring how Jupiter's speed changes during its elliptical orbit around the Sun. E) knowing the Sun's mass and measuring the average distance of Jupiter from the Sun.

measuring the orbital period and distance of Jupiter's orbit around the Sun.

The center of mass of a binary star system is

the balance point of the system, around which the two objects would revolve.