Ch.3-4

When light enters a medium from space it Choose one: A. slows down. B. speeds up. C. changes frequency. D. travels at the same speed.

A. slows down

A planet moves fastest when it is __________ to the Sun

closest

Not accelerating

constant speed

A net force must be acting when an object Choose one or more: A. accelerates. B. changes both speed and direction. C. changes speed but not direction. D. changes direction but not speed.

A.accelerates B.changes both speed and direction. C. changes speed but not direction. D. changes direction but not speed.

Pupil

Aperture

If the Moon were 2 times closer to Earth than it is now, the gravitational force between Earth and the Moon would be Choose one: A. 8 times stronger. B. 4 times stronger. C. 16 times stronger. D. 2 times stronger.

B. 4 times stronger.

Rank these types of light in order of INCREASING energy: orange, green, gamma ray, ultraviolet, infrared, radio

Radio Infrared Orange Green Ultraviolet Gamma Ray

Rank these types of light in order of increasing energy. (lower energy to higher)

Radio, Infrared, Orange, Green, Ultraviolet, Gamma Ray

Chromatic

Rainbow-making effect

Diffraction

Smearing effect due to sharp edge

Chromatic aberration

rainbow-making effect

Each elliptical path followed by the planets has two foci. At one focus is the_________ . At the other focus is ___________ .

sun; nothing.

How does the speed of light in a medium compare to the speed in a vacuum? Choose one: A. The speed in the medium is always slower than the speed in a vacuum. B. The speed in the medium is always faster than the speed in a vacuum. C. It's the same since the speed of light is a constant. D. The speed in the medium may be faster or slower, depending on the medium.

A. The speed in the medium is always slower than the speed in a vacuum.

Imagine you are walking along a forest path. Which of the following is not an action-reaction pair in this situation? Choose one: A. You push down on Earth; Earth pushes you forward. B. Your foot pushes back on the inside of your shoe; your shoe pushes forward on your foot. C. The gravitational force between you and Earth; the gravitational force between Earth and you. D. Your shoe pushes back on Earth; Earth pushes forward on your shoe.

A. You push down on Earth; Earth pushes you forward.

When a ball is tossed in the air and reaches the top of its arc, which of the following quantities are zero? Choose one or more: A. the acceleration of the ball B. the force on the ball C. the velocity of the ball D. the speed of the ball

C.the velocity of the ball D.the speed of the ball

Retina

CCD

If Earth were 8.5 times farther away from the Sun than it is now, how many times weaker would the gravitational force between the Sun and Earth be? ________ times weaker

72.25 times weaker

Interferometer

several telescopes connected to act as one.

The amplitude of a light wave is related to its Choose one: A. intensity. B. frequency. C. speed. D. color.

A. intensity

Optic

Wiring to computer

Aperature

diameter

Rank these wavelengths of light in order, according to their frequencies. (lowest frequency-to highest)

0.8 km, 5m , 7cm, 3um, 460 nm, 0.02 nm

Place the following in order from largest to smallest semi-major axis:

1. a planet with a period of 2 Earth years 2. a planet with a period of 1 Earth year 3. a planet with a period of 0.5 Earth years 4. a planet with a period of 84 Earth days

Both Kepler's laws and Newton's laws tell us something about the motion of the planets, but there are fundamental differences between them. What are the differences? Select all of the true statements. Choose one or more: A. Kepler defined laws based on one special case—the observed motions of planets in the Solar System, while Newton defined theoretical laws that describe the general behavior of all motions in the universe. B. Kepler reported how planets moved, and Newton explained why. C. Kepler's approach was empirical, while Newton's was theoretical. D. Kepler's discoveries built on the work of an earlier astronomer, while Newton's did not.

A. Kepler defined laws based on one special case—the observed motions of planets in the Solar System, while Newton defined theoretical laws that describe the general behavior of all motions in the universe. B. Kepler reported how planets moved, and Newton explained why. C. Kepler's approach was empirical, while Newton's was theoretical.

The resolution of radio telescopes suffers greatly from the large wavelengths of the light they are observing. What can be done to a radio telescope to improve its angular resolution? Choose one: A. Make its dish bigger. B. Increase the integration time. C. Fit it with adaptive optics. D. Put it in space.

A. Make its dish bigger.

Kepler's second law says that

A. Planets move fastest when they are closest to the Sun.

Besides adding adaptive optics to a telescope, what else can be done to reduce the effects of seeing? Choose one: A. Put the telescope at a higher altitude (the height above sea level). B. Build a larger telescope. C. Increase the integration time. D. Use a reflecting telescope instead of a refracting telescope.

A. Put the telescope at a higher altitude (the height above sea level).

Based on the above graph, which of these types of light from astronomical sources are not observable from the ground? Choose one or more: A. gamma ray B. infrared at 1 micrometer (10-6 m) C. infrared at 100 micrometer (10-4 m) D. visible E. ultraviolet at 100 nm F. X-ray G. radio at 1 meter

A. gamma ray C. infrared at 100 micrometer (10-4 m) E. ultraviolet at 100nm F. X-ray

An empirical science is one that is based on Choose one: A. observed data. B. calculus. C. computer models. D. hypothesis.

A. observed data

Resolution

Ability to distinguish objects that appear close together in the sky

Why is the Hubble Space Telescope in space instead of on the ground?

B. It avoids atmospheric distortion. C. It observes in the UV.

Imagine decreasing the size of the lens in the figure above. Which choice below best describes what would happen? Choose one: A. Less total light from the source will hit the lens, making it appear smaller on the detector. B. Less total light from the source will hit the lens, making it appear fainter on the detector. C. The lens will be more efficient at focusing light, making the source appear brighter on the detector. D. The lens will be more efficient at focusing light, making the source appear larger on the detector.

B. Less total light from the source will hit the lens, making it appear fainter on the detector.

Is the amplitude related to the wavelength or frequency? Choose one: A. The amplitude is inversely related to the wavelength or the frequency. B. The amplitude is not related to the wavelength or the frequency. C. The amplitude is directly related to the wavelength or the frequency.

B. The amplitude is not related to the wavelength or the frequency.

Choose all of the effects that would automatically happen if the wavelength of light were increased. Choose one or more: A. The amplitude of the wave would increase. B. The energy of the light would decrease. C. The frequency of the light would decrease. D. The energy of the light would increase. E. The amplitude of the wave would decrease. F. The speed of the light would decrease. G. The frequency of the light would increase. H. The speed of the light would increase.

B. The energy of the light would decrease. C. The frequency of the light would decrease.

Newton's second law says that the acceleration (a) of an object depends on its mass (m) by the equation: a= F/m F is the force that is causing the object to accelerate. In the case of dropping objects from a height, the force that causes them to accelerate toward the Earth is gravity. If the acceleration of objects dropped from a height does not depend on the object's mass (as shown by Galileo's experiment), what does this imply about the force of gravity? Choose one: A. The force of gravity is constant with mass. B. The force of gravity increases with increased mass. C. The force of gravity decreases with increased mass. D. Nothing can be determined about gravity from this information.

B. The force of gravity increases with increased mass.

How does the heliocentric model explain the retrograte motion of Mars? Choose one: A. The heliocentric model explains retrograde motion because Mars sometimes physically moves backward in its orbit around the Sun. B. The heliocentric model explains retrograde motion because Mars only appears to move backward as Earth passes it in its orbit around the Sun. C. The heliocentric model explains retrograde motion because epicycles result in the apparent backward motion of Mars. D. The heliocentric model does not explain the retrograde motion of Mars. 1st attempt Feedback How does the heliocentric model explain the retrograte motion of Mars? Choose one: A. The heliocentric model explains retrograde motion because Mars sometimes physically moves backward in its orbit around the Sun. B. The heliocentric model explains retrograde motion because Mars only appears to move backward as Earth passes it in its orbit around the Sun. C. The heliocentric model explains retrograde motion because epicycles result in the apparent backward motion of Mars. D. The heliocentric model does not explain the retrograde motion of Mars.

B. The heliocentric model explains retrograde motion because Mars only appears to move backward as Earth passes it in its orbit around the Sun.

Increase the wavelength, using the arrow key. What happens to the rate of the frequency counter? Choose one: A. The rate of the frequency counter increases. B. The rate of the frequency counter decreases. C. The rate of the frequency counter does not change.

B. The rate of the frequency counter decreases.

Based on the time frames given in the above figure, which of the following are implications of the finite speed of light? Choose one or more: A. Using a stopwatch precise to 1/10th of a second, the speed of light can be measured by an observer at the bottom of Mount Everest watching a light source at the top of Mount Everest. B. There would be a noticeable delay in communications at the speed of light between Earth and astronauts on the Moon. C. If the light of the Sun were suddenly extinguished, we wouldn't notice it from Earth for over 8 minutes. D. When we gaze at the Andromeda Galaxy, we are looking back in time to the way it used to appear millions of years ago. E. At the speed of light, it would take several months to travel to the nearest star. F. Some rear-ending automobile accidents may have occurred because of the delay in the time it took for the light from the leading car to reach the following driver's eyes.

B. There would be a noticeable delay in communications at the speed of light between Earth and astronauts on the Moon. C. If the light of the Sun were suddenly extinguished, we wouldn't notice it from Earth for over 8 minutes. D. When we gaze at the Andromeda Galaxy, we are looking back in time to the way it used to appear millions of years ago.

Astronauts in a space shuttle can float while orbiting Earth. Why are these astronauts weightless? Choose one: A. They are affected equally by the Moon's gravity and Earth's gravity. B. They are falling around Earth at the same rate as the shuttle. C. They and the space shuttle have escaped from Earth's gravity. D. Everything in the orbiting shuttle is shielded from Earth's gravity.

B. They are falling around Earth at the same rate as the shuttle.

Imagine a planet moving in a perfectly circular orbit around the Sun. Is this planet experiencing acceleration? Choose one: A. No, because its speed is not changing all the time B. Yes, because it is changing its direction of motion all the time C. No, because planets do not experience accelerations D. Yes, because it is changing its speed all the time

B. Yes, because it is changing its direction of motion all the time.

The resolution of the human eye is 1 arcminute, or 1/60th of a degree. If the light of two street lamps in the distance is separated by 0.5 arcminute, what will you see with your eyes? Choose one: A. two distinct lights B. a single light, with the combined brightness of each street lamp C. a single light that has been distorted into an egg shape

B. a single light, with the combined brightness of each street lamp

Light acts like Choose one: A. a particle. B. both a wave and a particle. C. neither a wave nor a particle. D. a wave.

B. both a wave and a particle.

All large astronomical telescopes are reflectors because Choose one or more: A. they retain better picture quality despite minor accidents. B. chromatic aberration is minimized. C. they are not as heavy. D. they require less maintenance. E. they can be shorter.

B. chromatic aberration is minimized. C. they are not as heavy. E. they can be shorter.

Kepler's second law says that if a planet is in an elliptical orbit around a star, then the planet moves fastest when the planet is Choose one: A. located at one of the foci. B. closest to the star. C. closest to another planet. D. farthest from the star.

B. closest to the star.

If you went to Mars, your weight would be Choose one: A. higher because you are closer to the center of the planet. B. lower because Mars has lower mass and a smaller radius that together produce a lower gravitational force. C. lower because Mars has two small moons instead of one big moon, so there's less tidal force. D. the same as on Earth.

B. lower because Mars has lower mass and a smaller radius that together produce a lower gravitational force.

In the video, the loaded car accelerated less than the unloaded car when the same force was applied. This was noticeable because the loaded car Choose one or more: A. was traveling faster after a little time had passed. B. reached the end of the track more slowly. C. reached the end of the track faster. D. was traveling less quickly after a little time had passed.

B. reached the end of the track more slowly. D. was traveling less quickly after a little time had passed.

Compared to your mass on Earth, on the Moon your mass would be Choose one: A. lower because the Moon is smaller than Earth. B. the same; mass doesn't change. C. lower because the Moon has less mass than Earth. D. higher because of the combination of the Moon's mass and size.

B. the same; mass doesn't change.

To what Solar System object does the arrow point? Choose one: A. Mercury B. the Sun C. Earth D. the Moon

B.the Sun

The bright, colorful "stripes" of a rainbow such as the one shown here follow a particular order. Rank each color of the rainbow by how much energy is carried by its electromagnetic waves, from highest to lowest. (most energy to least)

Blue, Yellow, Orange, Red

The planet Uranus will be observed in retrograde motion when Choose one: A. Uranus is closest to the Sun. B. Uranus is farthest from the Sun. C. Earth overtakes Uranus in its orbit. D. Uranus overtakes Earth in its orbit.

C. Earth overtakes Uranus in its orbit.

Which of Galileo's astronomical observations were best explained by a heliocentric model? Choose one or more: A. sunspots B. craters on the Moon C. moons of Jupiter D. phases of Venus

C. moons of Jupiter D. phases of Venus

The advantage of an interferometer is that Choose one: A. diffraction effects are dramatically decreased. B. the light-gathering power is dramatically increased. C. the resolution is dramatically improved. D. the focal length is dramatically increased. E. chromatic aberration is dramatically decreased.

C. the resolution is dramatically improved.

If the integration time is long enough to collect the light from this entire animation, what effect would seeing have on the image of the object? Choose one: A. It would create a double image, making one object look like two. B. It would sharpen the light from the object, making it appear brighter. C. It would blur the light from the object, effectively decreasing the angular resolution of the telescope. D. It would blur the light from the object, effectively increasing the angular resolution of the telescope.

D. It would blur the light from the object, effectively increasing the angular resolution of the telescope.

If you had a telescope with the same-sized lens (and same focal length) as the human eye, what would be the benefit of taking an exposure of a steady light source with an integration time of 10 seconds? Choose one: A. The resolution of the image would be better. B. There would be no benefit, because the dimensions of the telescope are the same as those of the human eye. C. The light source would appear larger in the image (higher magnification). D. The light source would appear brighter in the image.

D. The light source would appear brighter in the image.

Space telescopes that exist in orbit above most of Earth's atmosphere are expensive, so they must therefore be supported with a very compelling motivation. If you were trying to justify funding for a space telescope in orbit around the Earth, which of the following would be the best argument to use? Choose one: A. The telescope would avoid the effects of atmospheric seeing. B. The telescope would be able to observe 24 hours a day. C. The telescope would be physically closer to astronomical objects. D. The telescope could observe wavelengths of light that are not visible from the ground.

D. The telescope could observe wavelengths of light that are not visible from the ground.

A light wave does NOT require Choose one: A. a speed. B. a wavelength. C. a frequency. D. a medium in which to propagate.

D. a medium in which to propagate.

The angular resolution of a ground-based telescope is usually determined by Choose one: A. diffraction. B. the focal length. C. refraction. D. atmospheric seeing.

D. atmospheric seeing.

An object in a(n) __________ orbit in the Solar System will remain in its orbit forever. An object in a(n) __________ orbit will escape from the Solar System. Choose one: A. elliptical; circular B. unbound; bound C. circular; elliptical D. bound; unbound

D. bound; unbound

If we wanted to increase the Hubble Space Telescope's altitude above Earth and keep it in a stable orbit, we also would need to Choose one: A. decrease its weight. B. increase its weight. C. decrease its orbital speed. D. increase its orbital speed.

D. increase its orbital speed.

Aperture

Diameter

Focal length

Distance from lens to focal plane

Suppose you read in the newspaper that a new planet has been found. Its average speed in its orbit is 33 kilometers per second (km/s). When it is closest to its star, it moves at 31 km/s, and when it is farthest from its star, it moves at 35 km/s. This story is in error because Choose one: A. Kepler's third law says the planet has to sweep out equal areas in equal times, so the speed of the planet cannot change. B. the average speed is too fast. C. using these numbers, the square of the orbital period will not be equal to the cube of the semimajor axis. D. planets stay at a constant distance from their stars; they don't move closer or farther away. E. Kepler's second law says the planet must move fastest when it is closest, not when it is farthest away.

E. Kepler's second law says the planet must move fastest when it is closest, not when it is farthest away.

Place the names of the types of radiation in their correct places in the EM spectrum. (From left to right)

Gamma Rays, X-Rays, Ultraviolet, Visible light, Infrared, Microwaves, Radio

Accelerating

Increased speed Constant speed Decreased speed

Lens

Objective lens

resolution

ability to distinguish objects that appear close together in the sky

and slowest when it is _______ furthest from the Sun.

furthest

Newton's second law of motion states that

the acceleration of an object is proportional to the net force acting on it.