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Astro 7n Exam 1 (Unit 1 & 2) Quiz | 2024
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According to Newton's Second 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? Hint: Remember F = m * a - ✔✔Acceleration Increases If the earth were moved to half its current distance from the sun, how would the force of gravity by the sun on the earth change? Hint: Recall the form of the equation that you derived, earlier in the game: "gravitational acceleration (g) is proportional to the mass (m) of the body you are bound to, and INVERSELY proportional to the SQUARE of your distance (r) from its center mass," or g = m / (r * r) - ✔✔It would be four times stronger What did newton's law of universal gravitation tell us about how gravity works? Hint: Recall that the FORCE of gravity ('F = ma' or 'F = mg'), unlike gravitational acceleration (just the 'a' or 'g'), depends on the masses of two objects interacting -- remember that the 'g' in 'F = mg' is also dependent on a mass value (of a second object). - ✔✔The force of gravity from the sun will be stronger on an object with more mass The earth's radius is about 6400 km. If you were to orbit in the space station 150 km above the ground, the force of gravity you feel from earth would be...? Hint: think only about Newton's Law of Universal Gravitation. Recall the form of the equation that you derived earlier in the game: "gravitational acceleration (g) is proportional to the mass (m) of the body you are bound to, and INVERSELY proportional to the SQUARE of your distance (r) from its center mass," or g = m / (r * r) - ✔✔Slightly weaker than when you are standing on earth
If you were to sit on the ground ere would be a force due to gravity pulling you toward earth. which of the following is true according to newton's 3rd law? Hint: Remember each force has an equal and opposite reaction. - ✔✔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? Hint: Recall Newton's First Law of Motion (also referred to as "inertia"): "An object at rest will remain as rest unless acted upon by a force. An object in motion will continue in motion --- in a straight path and at constant velocity -- unless acted upon by a force, Think of a moment about the force of gravity between the Earth and the Sun, and which way or ways that force is directed. - ✔✔It would continue to move in a line in the same direction it was moving when the gravity turned off Consider a planet whose rotation axis is NOT tilted with respect to its orbital plane. What are the season's like on this planet? Hint: The seasons on Earth aren't caused by different distances from the Sun in different parts of the orbit. What are they caused by? - ✔✔There are no seasons If the Earth rotated on its axis more slowly than it does now... Hint: How long does it take for the Earth to rotate - ✔✔Its days would be longer If Earth has its orbit changed so that at all points along its orbit it was always the same distance from the sun (circular orbit), how would this affect the seasons on Earth? Hint: Remember that the orbit of the sun around the earth is an eclipse but that it is pretty close to being a circle - ✔✔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. Therefore....
Hint: Recall why we don't see a solar eclipse very often on earth (the moon orbits the earth in a different plane than the earth orbits the sun) - ✔✔Once every orbit of its moon (its month). From Earth, in which constellation might you find the planet Saturn? Hint: Remember that all the planets orbit the Sun in the same plane. What kind of constellation should they be in? (a zodiac constellation) - ✔✔Taraus Why don't we see the constellation Orion at night throughout the year? Hint: Orion is not a zodiac constellation - ✔✔As the 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? Hint: What object is in front of your zodiac constellation on your birthday, and what does that imply about when the constellation would be easiest to see clearly? - ✔✔At midnight six months after your birthday Constellations close to the North pole of Earth ________. Hint: Remember why the stars move over the course of a night. It has to do with the earth. - ✔✔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 any given time from a single location on a clear night? Hint: what fraction of the the sky can you see at any given time? - ✔✔ 44 What is the relationship between wavelength and frequency?
Hint: Think about...if you shake a rope fast, how far apart are the peaks of the waves? - ✔✔If the frequency increases the wavelength decreases Compare frequency of x-ray versus regular light. Hint: Remember that X-rays are dangerous. What would that mean about their energy? And how are energy and frequency related? - ✔✔The X-ray has a larger frequency than visible light Compare the frequency and wavelength of a gamma ray with visible light: Hint: Gamma rays are the highest energy form of radiation. What does that mean about frequency and wavelength? - ✔✔Gamma ray frequency is higher and its wavelength is lower If the frequency of radiation is twice as large then its wavelength is... Hint: Remember that wavelength and frequency are opposite. When one goes up, the other goes down by the same factor - ✔✔Half as large Compared to Blue light, red light has.... Hint: Red is not the hottest. Frequency is like energy. Wavelength is the opposite. - ✔✔Longer wavelength, smaller frequency, smaller energy What types of radiation have the lowest energy? Hint: The lowest energy is the longest wavelength. - ✔✔Infrared radiation and radio The spectrum of an oxygen lamp looks different than the spectrum of a sodium lamp because:
D. An electron can have any energy within an atom, so long as that energy is above the ground state energy. E. Ultraviolet light has the shortest wavelength of any electromagnetic radiation. - ✔✔C. An absorption spectrum appears as a continuous spectrum interrupted by a series of dark lines. The electrons in a cloud of hydrogen gas are making the transition from excited states to the ground state. what does the spectrum of this cloud of hydrogen gas look like? hint: What is emitted when an electron goes from a high energy level to a low energy level? - ✔✔It will consist of a few bright emission lines at specific wavelengths. In what ways does a 30 meter telescope outperform a 10 meter telescope? Hint: The important thing about a telescope is the area of its circular mirror - ✔✔Its images are 9 times brighter than a 10 meter Even the largest ground-based telescopes have resolution restrictions imposed by.... - ✔✔Atmospheric blurring of images When you magnify an object with a telescope, what else happens to your view of the sky? Hint: There are advantages and disadvantages to magnifying - ✔✔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? Hint: You have to consider the area of the circular mirror which goes like the diameter squared. And you have to consider how much less time it would take to collect the same amount of light with the larger telescope. - ✔✔15 minutes
If a telescope in space is only 1/4 of the diameter of a telescope on earth, which of the following is true? A. The larger telescope can observe objects for longer time periods that the space telescope. B. The larger telescope can observe objects fainter than the space telescope. C. The larger telescope collects less light than the space telescope. D. The space telescope has more light gathering power than the larger telescope on the ground. E. The space telescope has a high magnification than the larger telescope on the ground - ✔✔B. The larger telescope can observe objects fainter than the space telescope. Which of the following is not a characteristic of Jovian planets? - ✔✔They have a higher density than terrestrial planets Which planet has a moon with many sulfur volcanoes? - ✔✔Jupiter Which planets have a rocky, relatively dense composition? - ✔✔Mercury, Venus, Earth, and Mars What is true about Jupiter's moon lo? - ✔✔It has volcanic activity What properties characterize all the Jovian planets (compared to Terrestrial planets)? - ✔✔Many moons, large size, low densities What was Kepler's first law? - ✔✔Planets revolve around the sun in elliptical orbits with Sun at one focus of the ellipse What best describes the orbit of the Earth around the Sun? - ✔✔An ellipse that is close to being circular
Craters on Venus... - ✔✔Are about the same in size and structure to those on Earth, Moon and Mars Volcanoes on Venus... - ✔✔Produce very large lava flows that cover at least 85% of the Planet's surface Where do mountains on Earth come from? - ✔✔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? - ✔✔At locations near the poles What is NOT true about Earth's atmosphere? - ✔✔It has more Carbon Dioxide than Venus, so is heated more than Venus by the greenhouse effect What is ozone? - ✔✔Three oxygen atoms bonded together into a single molecule (O3) What would happen if the ozone layer were completely destroyed? - ✔✔Ultraviolet radiation from the sun would get through the atmosphere and cause damage to life Why is Venus's day so long? - ✔✔Venus's rotation time is very long compared to the time it takes to go once around the sun The Greenhouse effect: - ✔✔Is larger on Venus that on Earth Which two terrestrial planets have the least amount of atmosphere? - ✔✔Mars and Mercury The densities of the four terrestrial planets are similar to each other. This means: - ✔✔They are made of similar substances A meteor shower can occur when: - ✔✔Earth's orbit crosses a trail of debris left behind from a comet Most meteors: - ✔✔Are very small pieces of rock burning in the Earth's atmosphere
A comet's nucleus is composed of - ✔✔Dust dry ice and water ice The material in a meteorite is: - ✔✔Roughly as old as the solar system
