BROCK UNIVERSITY. 1. The observation that the intervals of time between two successive quarter phases of the Moon are very nearly equal implies that

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1 BROCK UNIVERSITY Page 1 of 10 Test 1: November 2014 Number of pages: 10 Course: ASTR 1P01, Section 2 Number of students: 961 Examination date: 7 November 2014 Time limit: 50 min Time of Examination: 17:00 17:50 Instructor: S. D Agostino Answer all questions on the scantron sheet provided. No aids permitted except for a non-programmable calculator. Each question is worth 1 mark. Total number of marks: The observation that the intervals of time between two successive quarter phases of the Moon are very nearly equal implies that (a) our distance from the Moon is much greater than our distance from the Sun. (b) Kepler s third law of planetary motion is valid. (c) our distance from the Sun is much greater than our distance from the Moon. (d) Newton s second law of motion is valid. 2. As observed from Earth, the other planets (a) always move from West to East relative to the stars. (b) generally move from West to East relative to the stars, but every now and then they reverse direction of motion and move from East to West. (c) always move from East to West relative to the stars. (d) generally move from East to West relative to the stars, but every now and then they reverse direction of motion and move from West to East. 3. The speed of a planet moving along an elliptical orbit is greatest when it is farthest from the Sun. (a) True (b) False 4. The first person to conclude from observations that the Milky Way consists of a vast number of very distant stars was (a) Aristotle. (b) Aristarchus. (c) Brahe. (d) Copernicus. (e) Galileo.

2 ASTR 1P01 November 2014 Page 2 of The ancient Greek thinker who observed that many things in nature are well-described by geometrical and mathematical relations was (a) Archaeopteryx of Jurassic. (b) Archimedes of Syracusa. (c) Genghis of Mongolia. (d) Loki of Marvel. (e) Pythagoras of Samos. 6. The apparent motions of the planets are close to the ecliptic because (a) the planes of the orbits of the planets are close to the plane of Earth s orbit. (b) only motions close to the zodiac are visible from Earth. (c) planets are visible only when the ecliptic and the celestial equator coincide. (d) the planet is visible only when the Sun, the Earth, and the planet are aligned. 7. Which of the following astronomers determined that gravity is responsible for keeping the Moon in its orbit around the Earth? (a) Copernicus. (b) Galileo. (c) Kepler. (d) Newton. 8. Newton lived about (a) 2400 years ago. (b) 1800 years ago. (c) 500 years ago. (d) 300 years ago. 9. Ptolemy lived about (a) 2400 years ago. (b) 1800 years ago. (c) 500 years ago. (d) 300 years ago. 10. A phenomenon that can be explained using the concept of inertia is (a) a ball moving in a circle at a constant speed. (b) a ball moving in a circle at a speed that is not constant. (c) an object that speeds up as it falls due to the influence of gravity. (d) a passenger in a car continuing to move forward when the brakes are applied to suddenly slow the car down.

3 ASTR 1P01 November 2014 Page 3 of The operation of a rocket in space is an example of Newton s third law in action, because (a) the force that the exhaust gases exert on the rocket is equal and opposite to the force that the rocket exerts on the exhaust gases. (b) the force that the rocket exerts on the fabric of spacetime is equal and opposite to the force that the fabric of spacetime exerts on the rocket s exhaust gases. (c) the force of the rocket s motion is equal and opposite to the force of the motion of the exhaust gases. (d) the force of the rocket s velocity is equal and opposite to the force of the velocity of the exhaust gases. 12. The prevailing medieval view was that the heavens were perfect and that celestial objects were eternal and unchanging. Observation of features on the Moon in the early 1600s by suggested that the Moon is a hunk of rock, not a perfect ethereal celestial object, and so helped humans to advance their understanding of the heavens. (a) Brahe (b) Copernicus (c) Galileo (d) Kepler 13. revived the ancient idea of that the Sun is the centre of the solar system. (a) Brahe, Aristarchus (b) Brahe, Hipparchus (c) Copernicus, Aristarchus (d) Copernicus, Hipparchus 14. One of Copernicus s great advances was to (a) determine the relative distances of each planet from the Sun. (b) measure the relative size of each planet. (c) precisely measure the relative brightness of each planet. (d) determine the composition of the atmosphere of each planet. 15. An advantage of the Renaissance heliocentric model of the solar system (over the geocentric model) is that (a) stellar parallax is easier to explain. (b) the apparent motion of the Sun through the zodiac is easier to explain. (c) the times of eclipses can be predicted more accurately. (d) the apparent retrograde motions of planets is easier to explain.

4 ASTR 1P01 November 2014 Page 4 of A powerful counter-argument against the Renaissance heliocentric model of the solar system was that (a) it makes no sense that the Sun moves. (b) planetary orbits are circular because the circle is the most perfect geometrical figure. (c) stellar parallaxes had not been observed up to that time. (d) the stars are themselves suns, with perhaps their own planets. 17. The pre-kepler heliocentric model of the solar system was no better than the geocentric model in predicting the locations of planets because (a) of the interference of the Catholic Church. (b) the model still assumed planetary orbits are circular. (c) of disagreements with Aristotle s great works. (d) the model failed to account for retrograde motion. 18. As described by Kepler s third law of planetary motion, (a) planets closer to the Sun have shorter periods. (b) planets closer to the Sun have longer periods. (c) the period of a planet does not depend on its distance from the Sun. (d) the period of a planet is related to its distance from the Sun, but not in a way described here. 19. If an asteroid s average distance from the Sun is about 4 AU then its orbital period is about (a) 8 years. (b) 4 years. (c) 16 years. (d) 2 years. 20. discovered that the orbits of planets around the Sun are ellipses. (a) Brahe (b) Copernicus (c) Galileo (d) Kepler

5 ASTR 1P01 November 2014 Page 5 of Each of the following statements is true. Which statement follows directly from Kepler s third law? (a) Venus is more massive than Mercury. (b) Venus orbits the Sun at a slower average speed than Mercury. (c) Venus is farther from the Sun than Mercury. (d) Venus has a thicker atmosphere than Mercury. 22. The first person to write about observing sunspots through a telescope was (a) Kepler. (b) Galileo. (c) Copernicus. (d) Brahe. 23. Which of the following observations was the strongest evidence (in the 1600s) for a heliocentric model of the solar system? (a) The moons of Jupiter. (b) Stellar parallax. (c) Sunspots. (d) The gibbous and quarter phases of Venus. 24. Who determined that gravity is responsible for keeping the Moon in its orbit around the Earth? (a) Copernicus. (b) Galileo. (c) Kepler. (d) Newton. 25. The prevailing medieval view was that all objects in the solar system orbit the Earth. Observation of moons of Jupiter in the early 1600s by suggested that objects in the solar system could orbit other objects, not just Earth, and so helped humans to advance their simplistic views of the heavens. (a) Copernicus (b) Galileo (c) Kepler (d) Newton

6 ASTR 1P01 November 2014 Page 6 of Which of the following was a valid argument against the heliocentric model proposed by some ancient Greek astronomers? (a) The Earth would lose its Moon if it were revolving around the Sun. (b) The heliocentric model contradicted the ideas of Aristotle. (c) Things would fall off the Earth if it were moving. (d) Stellar parallax was not observed. 27. An early estimate for the circumference of the Earth was made by the ancient Greek astronomer (a) Alexandria. (b) Aristotle. (c) Eratosthenes. (d) Syene. 28. The ancient Greek thinker named argued that the Earth cannot be flat, because a traveller moving south sees stars that were previously hidden below the previous horizon. (a) Anaximander (b) Archimedes (c) Aristarchus (d) Aristotle 29. The heliocentric model of the solar system probably arose because of (a) the estimate that the Sun is larger than the Earth made by Aristarchus. (b) the fact that the Sun is the king of the solar system in Greek mythology. (c) the thought that the Sun is made of fire, and fires were always placed at the centres of camps. (d) observations by the ancient Greeks that the Earth moves but the Sun does not move. 30. Stellar parallax was not observed by ancient Greek astronomers because (a) they didn t know it existed, and so didn t think to look for it. (b) they knew it existed, but looked in the wrong parts of the sky. (c) stellar parallax is only observable from outside the Earth s atmosphere. (d) their technology was not advanced enough to detect the minute parallax angles.

7 ASTR 1P01 November 2014 Page 7 of Epicycles were introduced into the ancient geocentric model of the solar system in an attempt to (a) account for anomalies in the motion of the Sun. (b) better describe planetary motions. (c) better predict eclipses. (d) explain why the planets have different rotational periods. 32. The angular size of the Sun the angular size of the Moon. (a) is much smaller than (b) is about the same as (c) is much larger than (d) can t be compared to 33. The Moon looks larger when it is near the horizon than when it is high in the sky because (a) of moisture in the Earth s atmosphere. (b) of refraction of light in the Earth s atmosphere. (c) this is an optical illusion. (d) of a temperature inversion in the Earth s atmosphere. 34. Ancient people noticed the difference between planets and stars by observing that (a) planets reflect the Sun s light, whereas stars create their own light. (b) planets are much closer to us than stars. (c) planets orbit the Sun whereas stars do not orbit the Sun. (d) planets are not fixed relative to the other stars. 35. The word planet originates from (a) an ancient Roman word that means child of the Sun. (b) an ancient Chinese word that means having no fixed position. (c) an ancient Celtic word that means moving in a circle. (d) an ancient Greek word that means wanderer. 36. Retrograde motions of planets (a) is difficult to explain if the Sun were the centre of the solar system. (b) is difficult to explain if the Earth were the centre of the solar system. (c) provides good evidence for the epicycle model of the solar system. (d) shows that the epicycle model of the solar system is false.

8 ASTR 1P01 November 2014 Page 8 of The planet Mercury is named after the mythological (a) king of the gods. (b) messenger god. (c) god of war. (d) goddess of love and beauty. (e) father of the king of the gods. 38. The planet Venus is named after the mythological (a) king of the gods. (b) messenger god. (c) god of war. (d) goddess of love and beauty. (e) father of the king of the gods. 39. According to Newton s laws of motion, an object moving in a circle at a constant speed is subject to a force pointing (a) along its trajectory (that is, tangent to its path). (b) away from the centre of the circle. (c) toward the centre of the circle. (d) [There is no net force on the object because the speed is constant.] 40. It is possible to determine the mass of a planet from the orbital data (the period and the orbital radius) of one of its satellites. (a) True. (b) False. 41. According to Newton s laws of motion the acceleration of a body (a) is proportional to the net force acting on it and inversely proportional to its mass. (b) is proportional to its mass and inversely proportional to the net force acting on it. (c) is independent of its mass. (d) is inversely proportional to the square of the net force acting on it.

9 ASTR 1P01 November 2014 Page 9 of Inertia is (a) the tendency of a body to remain at rest or moving in a straight line at constant speed. (b) the tendency of a body not to move. (c) the tendency of gases such as neon and argon not to enter into chemical reactions. (d) the tendency of a body to remain moving in a circle at a constant speed. 43. Newton s laws of motion state that if a body is neither at rest nor moving in a straight line at a constant speed, then (a) there must be a net force acting on the object. (b) the net force acting on the object is zero. (c) the net force acting on the object acts along the path of motion. (d) the net force acting on the object might or might not be zero, depending on the path of motion. 44. The motion of the Moon around the Earth is approximately circular, because (a) of the gravitational force that the Sun exerts on the Moon. (b) of the gravitational force that the solar system exerts on the Moon. (c) of the gravitational force that the Earth exerts on the Moon. (d) circular motion is the natural state of celestial objects found in the solar system, according to Newton s first law of motion. 45. The first scientist to propose that there must exist some force that holds the planets in their orbits (and in fact he incorrectly proposed that it is a magnetic force) was (a) Copernicus. (b) Galileo. (c) Kepler. (d) Newton. 46. The first scientist to propose a theory of gravity that was mathematical and to prove that an inverse-square force of gravity is consistent with celestial observations was (a) Galileo. (b) Hooke. (c) Huygens. (d) Newton.

10 ASTR 1P01 November 2014 Page 10 of If the net force acting on an object doubles in magnitude, but acts in the same direction, then (a) the acceleration of the object doubles. (b) the speed of the object doubles. (c) the velocity of the object doubles. (d) [None of the others.] 48. Your weight is (a) the same on Earth as it is on the Moon. (b) greater on Earth than it is on the Moon. (c) less on Earth than it is on the Moon. (d) [It depends on your state of motion in each location.] 49. If the distance between two bodies is increased by a factor of 2, the force of gravity each exerts on the other is (a) decreased by a factor of 2. (b) increased by a factor of 2. (c) decreased by a factor of 4. (d) increased by a factor of If the distance between two bodies is decreased by a factor of 3, the force of gravity each exerts on the other is (a) decreased by a factor of 3. (b) increased by a factor of 3. (c) decreased by a factor of 9. (d) increased by a factor of 9.