Smartwork 5 HW Flashcards

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Questions and Answers

Order the items from largest to smallest unit.

Solar system (correct)

Universe (correct)

Earth (correct)

Milky Way galaxy (correct)

A light year is a measure of?

Distance

If an event were to take place on the Sun, how long would it take for the light it generates to reach us?

8 minutes

Rank the following in order of smallest to largest.

Sun Signup and view all the answers

Rank the following in order smallest to largest.

Earth Signup and view all the answers

What does the cosmological principle state?

On a large scale, the universe is the same everywhere at a given time. Signup and view all the answers

What does Occam's razor state?

If two hypotheses fit the facts equally well, choose the simpler one. Signup and view all the answers

What is the significance of the cosmological principle?

Our place in the universe is not special. Signup and view all the answers

Order the steps of the scientific method.

Start with an observation or idea, suggest a hypothesis, make a prediction, perform a test or experiment or additional observation. Signup and view all the answers

What should be the next step in the scientific method after coming up with hypotheses?

Make predictions for each hypothesis, which will be observed if that hypothesis is correct. Signup and view all the answers

What is the scientific method?

A process by which scientists gain confidence in theories by failing to prove them wrong. Signup and view all the answers

Label these important reference points. Their location in your sky depends on your location on Earth.

Horizon, north celestial pole, zenith, celestial equator. Signup and view all the answers

Label these important places on the celestial sphere.

North celestial pole, south celestial pole, celestial equator, ecliptic. Signup and view all the answers

What is the celestial equator?

Is directly above Earth's equator. Signup and view all the answers

What is the horizon defined by?

The direction perpendicular to a line to the zenith. Signup and view all the answers

What causes day and night?

Rotation of the Earth on its axis. Signup and view all the answers

Why is Polaris, the North Star, unique?

It is the only star in the sky that doesn't move throughout the night. Signup and view all the answers

If the star Polaris has an altitude of 35°, then what do we know?

Our latitude is 35° north. Signup and view all the answers

Rank in lowest latitude to highest latitude.

NCP at 30 degrees Signup and view all the answers

Where on Earth can you stand and, over the entire year, see the entire sky?

At the equator. Signup and view all the answers

Looking down on Earth from above the North Pole, how does the Moon orbit Earth?

Counterclockwise. Signup and view all the answers

Which way do most objects travel when viewed from far above the North Pole of Earth?

Counterclockwise. Signup and view all the answers

About how long does it take Earth to go around its axis once?

1 day Signup and view all the answers

About how long does it take Earth to orbit the Sun?

365 days Signup and view all the answers

About how long does it take the Moon to orbit Earth?

29 days Signup and view all the answers

Rank from most full to least full.

Full moon, waning gibbous, waning crescent, new moon, waxing crescent, waxing gibbous. Signup and view all the answers

You see the Moon rising, just as the Sun is setting. What phase is the Moon in?

Full Signup and view all the answers

What causes the seasons?

The tilt of the Earth's axis. Signup and view all the answers

Why does the angle of the Sun's rays matter in regard to Earth's seasons?

They are more spread out if they strike at an angle. Signup and view all the answers

If Earth's axis were tilted by 45°, how would the seasons be different?

Winters would be colder. Signup and view all the answers

What would be the effect on seasons if Earth had the same tilt as Jupiter?

Seasons would be much less extreme. Signup and view all the answers

Label the northern hemisphere, solstices, and equinoxes.

Signup and view all the answers

What causes the seasons according to evidence about variations in the Sun's influence?

The tilt of the Earth's rotation axis to its orbit around the Sun causes parts of the Earth to experience more direct illumination. Signup and view all the answers

A lunar eclipse occurs when the shadow falls on the .

Earth's; Moon Signup and view all the answers

How did the ancients know the planets were different from the stars?

They saw that the planets move with respect to the stars over the course of many nights. Signup and view all the answers

What happens when Earth catches up to a slower-moving outer planet?

The outer planet exhibits retrograde motion. Signup and view all the answers

What inference can be made about the geocentric model concerning the motion of Mars?

The geocentric model is wrong because it falsely predicts that Mars should always move in the same direction with respect to the stars. Signup and view all the answers

What is the next step in the scientific process for the Copernican heliocentric model?

Make predictions from Copernicus's model, and verify them with observations. Signup and view all the answers

How does the heliocentric model explain the retrograde motion of Mars?

Because Mars only appears to move backward as Earth passes it in its orbit around the Sun. Signup and view all the answers

When will Uranus be observed in retrograde motion?

When Earth overtakes Uranus in its orbit. Signup and view all the answers

What defines an inferior planet?

An inferior planet is one that is closer to the Sun than Earth is. Signup and view all the answers

Superior Conjunction occurs when a planet is in line with the Earth and the Sun.

Signup and view all the answers

If a superior planet has a synodic period of 1.2 years, what is its sidereal period?

6 years Signup and view all the answers

What is the eccentricity of a circular orbit?

0 Signup and view all the answers

Highest eccentricity vs lowest eccentricity.

Eccentricity closest to 1 -- line. Eccentricity closest to 0 -- circle. As eccentricity increases, gets more stretched out. Signup and view all the answers

What is Earth's orbit's eccentricity?

eccentricity = 0.017 (circular) Signup and view all the answers

What does Kepler's second law say?

Planets move fastest when they are closest to the Sun. Signup and view all the answers

Match speed of planet in elliptical orbit:

A = Slowing down then speeding up B = Slowing down all the time C = Speeding up then slowing down Signup and view all the answers

Where is the slowest/highest speed traveled in an elliptical orbit?

A = Slowest speed traveled C = Highest speed traveled Signup and view all the answers

Kepler's second law says that if a planet is in an elliptical orbit around a star, then the planet moves fastest when it is?

Closest to the star. Signup and view all the answers

Sort each scenario into the category indicating whether or not the car is accelerating.

Accelerating -- decreased speed, increased, constant speed. Not accelerating -- constant speed. Signup and view all the answers

If you use the same force to push on two different cars, which will have the bigger acceleration?

The less massive one. Signup and view all the answers

If you push with a different force on two cars of the same mass, which car will have the bigger acceleration?

The car you pushed with the larger force. Signup and view all the answers

Imagine a planet moving in a perfectly circular orbit around the Sun. Is this planet experiencing acceleration?

Yes. It is changing its direction of motion all the time. Signup and view all the answers

Rank each object being pushed in order of increasing acceleration.

1 = 2m F = 0 2 = 2m F 3 = m F 4 = m 2F Signup and view all the answers

Imagine you are walking along a forest path. Which of the following is not an action-reaction pair in this situation?

You push down on Earth; Earth pushes you forward. Signup and view all the answers

Place the following in order from largest to smallest semimajor axis.

Planet with period of 2 earth years, 1 earth year, 0.5 earth years, 84 earth days. Signup and view all the answers

The period of Mars's orbit is 1.88 years. What is the distance of Mars's semimajor axis?

1.52 AU Signup and view all the answers

Halley's Comet has an orbital period of 76 years. What is the semimajor axis of its orbit?

17.9 AU Signup and view all the answers

Compared to your mass on Earth, on the Moon your mass would be?

The same; mass doesn't change. Signup and view all the answers

If you went to Mars, your weight would be?

Lower because Mars has lower mass and a smaller radius that together produce a lower gravitational force. Signup and view all the answers

If the acceleration of objects dropped from a height does not depend on the object's mass, what does this imply about the force of gravity?

The force of gravity increases with increased mass. Signup and view all the answers

Compare the gravity between these pairs, each consisting of an Earth-like planet and its star.

Lowest gravity: 1M earth/2M solar/2 AU; Highest gravity: 2M earth/1M solar/1 AU. Signup and view all the answers

Astronauts in a space shuttle can float while orbiting Earth. Why are these astronauts weightless?

They are falling around Earth at the same rate as the shuttle. Signup and view all the answers

If your mass is 85 kg, what would be your approximate mass and weight on Mars?

Mass 85 kg; weight 310 N. Signup and view all the answers

Assume your mass is 81.00 kg. Then your weight on Earth is 793.80 newtons. What would be your mass and weight on Mars?

Mass on Mars - 81 kg, weight on Mars - 301.64 N. Signup and view all the answers

If Earth shrank to a smaller radius but kept the same mass, how would the gravitational force between Earth and the Moon change?

Stay the same. Signup and view all the answers

Newton's third law implies what about the force of gravity associated with a person standing on Earth?

The Earth's gravity pulls downward on the person, and the person's gravity pulls upward on the Earth. Signup and view all the answers

Label smallest to greatest force.

Smallest force: m, m, 1.5r; Greatest force: m, 2m, r. Signup and view all the answers

If the distance between Earth and the Sun were cut in half, how would the gravitational force between these two objects change?

Increase by a factor of 4. Signup and view all the answers

For a pair of objects, where is the center of mass located?

Along the line between the two objects, closer to the more massive object. Signup and view all the answers

The connection between gravity and orbits enables astronomers to measure the __________ of stars and planets.

Masses. Signup and view all the answers

If you are transported to a planet with twice the mass of Earth, but the same radius of Earth, how would your weight change?

Increase; by a factor of 2. Signup and view all the answers

If the mass of Earth were increased by a factor of 4.00, how many times would the force between Earth and the Sun increase?

What likely causes Kepler's observation that planets travel faster when they are closer to the Sun?

The force of gravity is stronger closer to the Sun. Signup and view all the answers

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.

Bound; unbound. Signup and view all the answers

The primary factor in Earth's tides is?

The Moon's gravity. Signup and view all the answers

High tides vs low tides.

High - 0 & 180 degrees; Low - 90 & 270 degrees. Signup and view all the answers

Where do subsequent semi-diurnal (twice daily) tides happen precisely?

Once every 12 hours and 25 minutes. Signup and view all the answers

If the Moon had twice the mass that it does, how would the strength of the lunar tides change?

The highs would be higher and the lows would be lower. Signup and view all the answers

What causes the second high tide?

Weaker gravity pulling on Earth on the side opposite the Moon. Signup and view all the answers

When do spring tides occur?

When the Moon is in new or full phase. Signup and view all the answers

What causes the Moon to always keep the same face toward Earth?

Tidal locking. Signup and view all the answers

What does the effect of Earth's off-center bulge on the Moon imply?

The Moon used to be closer to Earth than it is now. Signup and view all the answers

What happens to the Earth's day due to rotation and the position of the Moon?

The Earth's day will become longer with time. Signup and view all the answers

If an object crosses from farther to closer than the Roche limit, it?

May be torn apart. Signup and view all the answers

How might you improve your chances of detecting the motion of light?

Move farther away from the light source. Signup and view all the answers

If the Sun instantaneously stopped giving off light, what would happen on Earth?

Earth would get dark 8 minutes later. Signup and view all the answers

A light wave does NOT require?

A medium in which to propagate. Signup and view all the answers

When light enters a medium from space, it?

Slows down. Signup and view all the answers

Light acts like?

Both a wave and a particle. Signup and view all the answers

Rank the longest wavelength to shortest wavelength.

Longest wavelength: Radio waves, Infrared, Visible, Ultraviolet, Gamma rays. Signup and view all the answers

Rank the lowest energy to highest energy.

Lowest energy: Radio; Infrared; Orange; Green; Ultraviolet; Gamma ray. Signup and view all the answers

Rank types of radiation from least energy to most energy.

Least energy: Radio waves; Infrared; Red visible light; Blue visible light; X-rays; Gamma rays; Most energy. Signup and view all the answers

When an electron moves from a higher energy level to a lower energy level in an atom, what happens?

A photon is emitted. Signup and view all the answers

How does the spectrum of a distant star reveal the star's chemical composition?

Dark lines, also called absorption lines, within the spectra are 'fingerprints' for the different atoms and molecules within a star's atmosphere. Signup and view all the answers

Study Notes

Cosmic Structure and Light

Items ordered from largest to smallest unit: Universe, supercluster, local group, Milky Way galaxy, solar system, Earth.
A light year measures distance.
Light from the Sun takes 8 minutes to reach Earth.
Rank from smallest to largest: Earth, Sun, solar system, Milky Way, Virgo supercluster, Universe.

The Cosmological Principle and Scientific Method

The cosmological principle asserts that the universe is uniform on a large scale and our location is not unique.
Occam's razor advocates for choosing the simpler hypothesis when two fit the facts equally.
The scientific method involves observations, hypothesis formulation, predictions, and testing.

Celestial Reference Points and Earth's Rotation

Label important celestial reference points: Horizon, north celestial pole, zenith, celestial equator.
The celestial equator is above Earth’s equator.
Day and night result from Earth's rotation on its axis.
Polaris remains in the same position in the night sky, indicating location.

Variations in Sky and Seasons

Earth's axial tilt causes seasonal changes and affects sunlight angles, with more direct illumination leading to warmer seasons.
If Earth's tilt was 45°, winters would be significantly colder.
The Moon's phases include Full, waning gibbous, waning crescent, new moon, waxing crescent, waxing gibbous.

Gravity and Tides

Tides are primarily influenced by the Moon's gravity, with high tides occurring at 0° and 180°, and low tides at 90° and 270°.
The gravitational force between Earth and another body increases if the distance is reduced.

Kepler's Laws and Planetary Motion

Kepler’s second law states that planets travel fastest when closest to the Sun.
Retrograde motion occurs when Earth overtakes an outer planet, causing the planet to appear to move backward.
An inferior planet orbits within Earth's orbit relative to the Sun.

Orbits and Gravity

Objects in bound orbits remain within the solar system; unbound orbits can lead to escape.
The center of mass between two objects is closer to the more massive object.
Gravitational force would quadruple if Earth-Sun distance is halved.

Properties of Light

Light waves do not require a medium to propagate, slowing down when entering a material from space.
Light exhibits both wave and particle properties.
A shift in energy levels of electrons in an atom results in photon emission.

Spectrum Analysis

Spectral analysis shows chemical composition via absorption lines unique to various atoms and molecules.

Studying That Suits You

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Description

Test your knowledge with these flashcards covering key astronomical concepts from Smartwork 5. You'll rank astronomical units and understand important measurements like light years. Perfect for reinforcing your understanding of space and distance!