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PSU Astro 7N Midterm Exam With 100%
Correct Answers 2024
According to Newton's 2nd law of motion, if the net force acting on the object increases while the mass of the object remains constant, what happens to the acceleration? - Correct Answer-Acceleration increases If Each were moved to half its current distance from the sun how would the force of gravity by the sun on Earth change? - Correct Answer-4x stronger what did Newton's Law of Universal Gravitation tell us about how gravity works? - Correct Answer-The force of gravity will be stronger on an object with more mass The Earth radius is about 6400 km. If you were in orbit in the space station 150km above the ground, the force of gravity you feel from Earth would be - Correct Answer-slightly weaker than when you are standing on Earth If you were to sit on the ground, there would be a force due to gravity pulling you toward the Earth. Which of the following is
true according to Newton's 3rd law? - Correct Answer-You are pushing the Earth away from yourself with the same force What would happen to the Earth if the sun's gravity somehow "turned off" instantaneously? - Correct Answer-It would continue to move in a line in the same direction it was moving when gravity turned off Consider a planet whose rotation axis is NOT titled with respect to its orbital plane. What are these seasons like on this planet? - Correct Answer-There are no seasons If the Earth rotated on its axis more slowly than it does now: - Correct Answer-Days would be longer If Earth had its orbit changed so that all points along its orbit were always the same distance from the sun(circular orbit), how would this affect the seasons on Earth? - Correct Answer- They would be the same as they are now A new planet orbits its star faster than the Earth orbits the sun and it rotates more slowly than the Earth rotates. Which of
From Earth, in which constellation might you find the planet Saturn? - Correct Answer-Taurus Why don't we see the constellation Orion at night all throughout the year? - Correct Answer-As Earth orbits the sun, its nighttime side points to different constellations at different points along its orbit When is the best time for you to be able to see the constellation that is your sign of the zodiac? - Correct Answer- At midnight 6 months after your birthday Constellations close to the North Pole of Earth _____ - Correct Answer-Move in a circle around the North Star, Polaris, over the course of a single night There are a total of 88 constellations. Roughly how many of these can be seen at a given time from a single location on a clear night? - Correct Answer-
What is the relationship between wavelength and frequency?
- Correct Answer-If the frequency increases, wavelength decreases Compare the frequency of x-ray versus regular light - Correct Answer-The x-ray has a larger frequency than visible light Compare the frequency and wavelength of a gamma ray with that of visible light: - Correct Answer-Gamma ray frequency is higher and its wavelength is lower Compared to blue light, red light has - Correct Answer-Longer wavelength, smaller frequency, smaller energy Which types of radiation have the lowest energy? - Correct Answer-Infrared radiation and radio The spectrum of an oxygen lamp looks different than the spectrum of a sodium lamp because: - Correct Answer-Each atom has a unique set of electron orbits
Even the largest ground-based telescopes have resolution restrictions imposed by: - Correct Answer-Atmospheric blurring of images When you magnify an object with a telescope, what else happens to your view of the sky? - Correct Answer-Your field of view gets smaller, so you can only see a small area of the sky How long would one need to observe a star on a 10 meter telescope to collect the same amount of light as one collects in one hour on a 5 meter telescope? - Correct Answer- minutes If a telescope in space is only 1/4 the diameter of a telescope on Earth, is this statement true or false: the larger telescope can observe objects fainter that the space telescope - Correct Answer-True What was Kepler's first law? - Correct Answer-Planets revolve around the sun in elliptical orbits with the sun at one focus of the ellipse
What best describes the orbit of the Earth around the sun? - Correct Answer-An ellipse that is close to being circular What does Kepler's second law support? - Correct Answer- When a planet is closer to the Sun, its speed is greater than when it is farther away How did Kepler himself originally state his second law? - Correct Answer-A line joining a planet and the sun sweeps out equal areas in equal intervals of time What was Kepler's third law? - Correct Answer-The square of the time period for an orbit of a planet is proportional to cube of its average distance from Sun (in other words P2 is proportional to a3) Saturn is about 10x as far from the sun as Earth is (a=10 AU). About how many times does Earth orbit the sun in the time it takes Saturn to orbit just once? - Correct Answer-About 30 Besides, the discovery that moons orbit Jupiter, what other discovery made by Galileo Galilei, with an early telescope,
Volcanoes on Venus: - Correct Answer-produce very large lava flows that cover at least 85% of the planet's surface Where do mountains on Earth come from? - Correct Answer- In some locations, plates of rock on the planet's surface press together and the plates rise together Where are aurorae likely to be seen most frequently? - Correct Answer-At locations near the poles What is NOT true about Earth's atmosphere - Correct Answer- It has more carbon dioxide than Venus, so is heated more than Venus by the Greenhouse effect What us ozone? - Correct Answer-3 oxygen atoms bonded together in a single molecule What would happen if the ozone layer were completely destroyed? - Correct Answer-UV radiation from the sun would get through the atmosphere and cause damage to life
Why is Venus's day so long (a day-night cycle on Venus lasts for as long as 243 Earth day and night cycles)? - Correct Answer-Venus's rotation time is very long compared to the time it takes to go once around the sun The Greenhouse effect: - Correct Answer-Is larger on Venus than on Earth The densities of the four Terrestrial planets are similar to each other. This means - Correct Answer-They are made of similar substances A meteor shower can occur when: - Correct Answer-Earth's orbit crosses a trail of debris left behind from a comet Most meteors: - Correct Answer-Are very small pieces of rock burning in the Earth's atmosphere A comet's nucleus is composed of: - Correct Answer-Dust, dry ice, and water ice The material in a meteorite is: - Correct Answer-Roughly as old as the solar system
What season is it in the Southern hemisphere when it is summer in the Northern hemisphere? - Correct Answer- Winter What happens to the moon in 1 month? - Correct Answer-It moves once around the Earth What causes the phases of the Moon? - Correct Answer-The Sun is lighting up different fractions of the part of the Moon we see from Earth What is the order of the phases of the Moon? - Correct Answer-New, Waxing Crescent, First quarter, Waxing Gibbous, Full, Waning Gibbous, Third Quarter, Waning Crescent When is the full moon visible? - Correct Answer-Only at night. It transits (is highest in the sky, or overhead) at midnight; the full moon rises 6 hours earlier (at sunset), and sets 6 hours later (at sunrise) When is the new moon visible? - Correct Answer-The new moon is visible during the day. It transits at noon; it rises 6 hours earlier (at sunrise), and sets 6 hours later (at sunset)
How are the Sun, Earth, and Moon positioned when it is new Moon? - Correct Answer-In a straight line: Sun, moon, Earth How are the Sun, Earth, and Moon positioned when it is full Moon? - Correct Answer-Sun, Earth, moon What is a solar eclipse? - Correct Answer-The Moon is blocking the Sun's light, or a location on the Earth's surface is passing under the Moon's shadow How are the Sun, Earth, and Moon positioned when it is a solar eclipse? - Correct Answer-Sun, moon, Earth(as in new moon) What is a lunar eclipse? - Correct Answer-Earth's shadow passes across the Moon How are the Sun, Earth, and Moon positioned when it is a lunar eclipse, and what phase is the Moon in? - Correct Answer-Sun, Earth, moon(as in full moon)
Describe a bluer color light in terms of its energy, frequency, and wavelength - Correct Answer-High-energy light, high frequency, low/short wavelength Describe a redder color light in terms of its energy, frequency, and wavelength - Correct Answer-Low-energy light, low frequency, high/long wavelength What kinds of radiation get through the Earth's atmosphere? - Correct Answer-Visible and radio What is a continuum spectrum? - Correct Answer-Light at all wavelengths What is an absorption spectrum? - Correct Answer-Shows absorption lines, dark lines in the spectrum at certain wavelengths, superimposed on a continuum spectrum and produced by a (less-energetic) gas cloud in front of a light source What is an emission spectrum? - Correct Answer-Shows emission lines, bright lines at specific wavelengths, in an
otherwise empty (dark) spectrum, due to emission of photons from atoms in gas that have electrons in elevated levels Reflecting telescopes use what to collect focus and light? - Correct Answer-A mirror Refracting telescopes use what to collect focus and light? - Correct Answer-A lens How many astronomical units are between the Earth and the Sun? - Correct Answer- What two properties of a planet affect the gravity we feel on its surface? - Correct Answer-Mass and radius Two planets have the same radius. If Planet A is 5 times more massive than Planet B, how does gravity differ on the surfaces of the two planets? - Correct Answer-Gravity is 5 times stronger on Planet A Say that there were a Planet X in our Solar System with a mass 1/4 the mass of Earth and a radius 1/2 the radius or Earth. How will the gravity on its surface compare to the surface
Ursa Minor is not a Zodiac constellation. - Correct Answer- True A particular Zodiac constellation is high in the sky at midnight in April. Where will it be in October? - Correct Answer-Near the Sun in the daytime sky What do you expect the spectrum of an object that is 1,000,000 Kelvin to be like? - Correct Answer-It should peak at X-ray wavelengths As compared to a cool star, a hotter star emits... - Correct Answer-Shorter wavelength, higher frequency, bluer color Radio waves can travel large distances without interference because... - Correct Answer-They have longer wavelengths than visible light Compared to ultraviolet radiation, X-rays have a wavelength that is... - Correct Answer-Shorter Star A is 4000 K, and Star B is 8000 K. True or false: The color of Star A is redder than Star B. - Correct Answer-True
A star is a hot, dense gas surrounded by a cooler, low density atmosphere. What type of spectrum will a star create? - Correct Answer-Absorption spectrum What makes a transition from a lower energy state to a higher energy state when a photon is absorbed into an atom? - Correct Answer-Electron An emission line is produced when: - Correct Answer-An electron passes from a higher to a lower energy level Bright lines in an emission spectrum represent: - Correct Answer-Particular energies of light that are emitted from a distant object The faintness of an object that a telescope can observe is mostly determined by... - Correct Answer-The diameter of the opening of the telescope In what ways does a 5 meter telescope outperform a 1 meter telescope? - Correct Answer-Its images are 25 times brighter than a 1 meter
