Exam 1 HW

How many arcseconds are in 1°?

3,600

The Milky Way can be seen only from the Northern Hemisphere. T/F

False

Rank the seasons for the Southern Hemisphere based on Earth's distance from the Sun(Closest to farthest)

Summer, Fall, Spring, Winter

Which of the following statements about the celestial sphere is not true?

The "celestial sphere" is just another name for our universe.

opaque

absorbs most light.

Our ________ is moving toward the star Vega at about 70,000 km/hr.

solar system

forms of light in order from highest to lowest energy.

Radio infrared visible ultraviolet X Rays gamma Rays

a planet moves faster in the part of its orbit nearer the Sun and slower when farther from the Sun, sweeping out equal areas in equal times.

Kepler's second law of planetary motion

X-ray telescope mirrors are very similar to optical telescope mirrors. T/F

False

If two objects are the same size but one object is 3 times hotter than the other object, the hotter object emits

81 times more energy

acceleration of gravity of Earth?

9.8 m/s2 downward

A radio telescope and an optical telescope of the same size have the same angular resolution T/F

False

If you double the mass of fusion material in a hydrogen bomb, you quadruple the amount of energy generated. T/F

False

The greater the wavelength of light, the greater its energy.

False

The observable universe is the same size today as it was a few billion years ago. T/F

False

What makes the North Star, Polaris, special?

It appears very near the north celestial pole.

the orbit of each planet about the Sun is an ellipse with the Sun at one focus.

Kepler's first law of planetary motion

The Milky Way and Andromeda galaxies are among a few dozen galaxies that make up our __________

Local Group

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

Longer wavelength means lower frequency and lower energy.

Our entire solar system orbits around the center of the __________ about once every 230 million years.

Milky Way Galaxy

Newton's first law of motion: an object moves at constant velocity if there is no net force acting upon it.

Newton's first law of motion:

force = mass x acceleration

Newton's second law of motion

for any force, there is an equal and opposite reaction force.

Newton's third law of motion

When we look into the band of light in our sky that we call the Milky Way, can we see distant galaxies?

No, because the stars, gas, and dust of the Milky Way block us from seeing them, however we can see close galaxies.

cause of our seasons

The tilt of Earth's axis causes different portions of the Earth to receive more or less direct sunlight at different times of year.

law of conservation of energy?

The total quantity of energy in the universe never changes.

Which of the following statements about circumpolar stars is true at all latitudes?

They always remain above your horizon.

Suppose you watch a leaf bobbing up and down as ripples pass it by in a pond. You notice that it does two full up and down bobs each second. Which statement is true of the ripples on the pond?

They have a frequency of 2 hertz.

If you are driving at 30 miles per hour and increase your speed to 60 miles per hour, you quadruple your kinetic energy. T/F

True

Most astronomical objects emit light over a broad range of wavelengths.

True

X-rays always have more energy than radio waves.

True

Due to its much higher density, water heated to 80 degrees (Celsius) contains more ________ energy than air at the same temperature.

thermal

Rank the seasons for the Northern Hemisphere based on Earth's distance from the Sun (closest to furthest)

Winter, Spring, Fall, Summer

The North Celestial Pole is 30 ∘ above your northern horizon. What does it tell you?

You are at latitude 30 ∘ N.

Which of the following best describes the modern definition of a constellation?

a region of the celestial sphere

According to the universal law of gravitation, if you triple the distance between two objects, then the gravitational force between them...

decreases by a factor of 9

Newton's first law of motion,

an object in motion will remain in motion unless acted upon by another force

An apple contains ________ energy that your body can convert into other forms energy.

chemical potential

When an electron in an atom goes from a higher energy state to a lower energy state, the atom

emits a photon of a specific frequency.

An asteroid that is moving farther from the Sun is gaining _________ energy

gravitational potential

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

have wavelengths that are longer than normal.

someone in the Andromeda galaxy is looking at Earth right now. They would see Earth...

how looked in the past

Which forms of light are lower in energy and frequency than the light that our eyes can see?

infrared and radio

According to the universal law of gravitation, the force due to gravity is

inversely proportional to the square of the distance between objects.

Rapidly moving comets have more _______energy than slowly moving ones.

kinetic

Nuclear fusion in stars converts some of the _______ energy of hydrogen nuclei into light and heat.

mass

What quantities does angular momentum depend upon?

mass, velocity, and radius

Kepler's third law of planetary motion

more distant planets orbit the Sun at slower average speeds, obeying the precise mathematical relationship p2 =a3.

You are one year older each time Earth _______ about the Sun.

orbits

The light from Polaris travels through space in the form________ of energy.

radiative

The Sun appears to rise and set in our sky because Earth _______ once each day.

rotates

What is the ecliptic?

the Sun's apparent path along the celestial sphere

The center of mass of a binary star system is

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

On average, galaxies are getting farther apart with time, which is why we say our __________ is expanding.

universe

When would you feel weightless?

while falling from a roof