Astronomy

Which of the following does not have a net force?

An elevator moving up at a constant speed

What is required to change an object’s angular momentum?

a twisting force

A rock held above the ground has

potential energy

If you double the distance between two objects, the gravitational force force between them

is ¼ the original force

If you double the mass of one of the objects and keep the distance the same, the gravitational force between them

doubles

If you double the mass of one of the objects and double the distance between them, the gravitational force between them

is ½ the original force

If you double the mass of both objects, and double the distance between them, the gravitational force between them

remains the same

The Voyager II spacecraft, which has visited all of the giant planets and is now on its way out of the solar system, is travelling at least

at a speed of 11 km/s on an unbound orbit

Why is a violet purple?

The violet reflects purple light

The lower the photon energy

the longer its wavelength

Everything looks orange through an orange filter because

The filter transmits the orange light and absorbs other colors

What kind of spectrum would a neon gas
tube show?

emission

What kind of spectrum would the star
Betelgeuse show?

absorption

Which is hottest?

a blue star

Why don’t we glow in the dark?

People only emit light that is invisible to our
eyes

I measure a line in the lab at 500.7 nm. The same line in a star has a wavelength of 502.8 nm. What can I say about this star?

It is moving away from me

I measure a line in the lab at 500.7 nm. The same line in a star has a wavelength of 500.7 nm. What can I say about this star?

It is moving perpendicularly

What probe crashed into Mercury almost 10 years ago?

Messenger

Why are Mars‘ volcanos so tall?

It has no plate tectonics and low surface gravity

What process created the elements from which the terrestrial planets were made?

Nuclear fusion in stars

Which planet is the least dense?

Saturn

___emits 2x as much heat as it receives from the Sun, due to contraction.

Jupiter

Which moon is responsible for Jovian auroras?

Io

Io’s torus around Jupiter is fed by Io’s ___.

gases

Jupiter does not have a large metal core like the Earth. How can it have a magnetic field?

It has metallic hydrogen inside, which circulates and makes a magnetic field.

How does Io get heated by Jupiter?

Tidal resonance

This moon has volcanoes.

Io

This moon has an atmosphere.

Titan

This moon is the largest in the solar system.

Ganymede

This moon has a salt water ocean.

Europa

What shape are moons?

large ones are spherical, small ones irregular

Why do Jupiter, Saturn, Uranus, and Neptune
all have rings?

All have small moons and orbiting particles that
constantly collide and make rings

If a material is highly opaque, then it

absorbs most light

When light reflects off an object, what is the relation between the angle of incidence and the angle of reflection?

angle of incidence = angle of reflection

If a material is transparent, then it

transmits light well.

Grass appears green because

it reflects green light and absorbs other colors.

Everything looks red through a red filter because

the filter transmits red light and absorbs other colors.

The frequency of a wave is

All of the above

The wavelength of a wave is

the distance between two adjacent peaks of the wave.

How are wavelength, frequency, and energy related for photons of light?

Longer wavelength means lower frequency and lower energy.

From lowest energy to highest energy, which of the following correctly orders the different categories of electromagnetic radiation?

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

From shortest to longest wavelength, which of the following correctly orders the different categories of electromagnetic radiation?

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

Which of the following statements about X rays and radio waves is not true?

X rays travel through space faster than radio waves.

Which of the following statements about X rays and radio waves is not true?

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

We can see each other in the classroom right now because we

reflect visible light.

Without telescopes or other aid, we can see the Moon because it

reflect visible light.

Spectra from neutral atoms compared with spectra from ionized atoms of the same element

have different sets of spectral lines.

Which of the following statements about thermal radiation is always true?

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

A gas heated to millions of degrees would emit

mostly X rays.

The spectra of most galaxies show redshifts. This means that their spectral lines

have wavelengths that are longer than normal.

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?

The star is moving toward us

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?

The galaxy is moving away from you.

If one object has a large redshift and another object has a small redshift, what can we conclude about these two objects?

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

If we observe one edge of a star to be redshifted and the opposite edge to be blueshifted, what can we conclude about the star?

The star is rotating.

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.)

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?

The line in the faster rotating star is broader.

What has the shortest wavelength? The longest?

gamma rays; radio waves

What has the lowest frequency? The highest?

radio waves; gamma rays

What has the lowest energy? The highest?

radio waves; gamma rays

What is the difference between the speed of light forms?

Nothing

Hot gas in Mars's upper atmosphere produces ___ in the ultraviolet portion of its spectrum.

emission lines

Carbon dioxide in Mars's atmosphere produces ___ in the infrared portion of its spectrum.

absorption lines

We determine Mars's surface temperature from the peak wavelength of the___ it emits.

thermal radiation

The color of Mars in our sky is determined by the ____ of Mars's spectrum.

visible portion

The ____ allows us to determine how fast Mars is moving toward or away from us.

Doppler Effect

Why does Mars appear reddish in color? 

It reflects most of the Sun's red light while absorbing most of its blue light. 

Suppose that Mars had a higher surface temperature. How would its spectrum be different?

The peak in the infrared would be at shorter wavelength

Which of the following procedures would allow you to make a spectrum of the Sun similar to the one shown, though with less detail?

Pass a narrow beam of sunlight through a prism.