PHY 109: Astronomy and Cosmology The Solar System
Fall 2003 Prof. Cote's Website • Astronomy at Rutgers • Department of Physics & Astronomy • Rutgers University
Last updated October 7, 2003
First Midterm: Solutions
Note that the order of the questions given here may differ from that on your exam.
Who first measured the circumference of the Earth?
Eratosthenes. Plato. Anaxagoras. Democritus. Euclid.
The physical force which controls the structure of the nucleus and binds together protons and neutrons is
the gravitational force the strong nuclear force the weak nuclear force the electromagnetic force the delta force.
Which of the following is a basic assumption of Science?
All objects in the universe are detectable. Einstein's theory of relativity is correct. The laws of Nature are the same everywhere in the universe. All theories are derivable from previous theories. Observations have little or no connection with the development of new models.
Which of the following types radiation has the longest wavelength?
Radio waves. Visible light. Infrared light. Ultraviolet light. Gamma rays.
In a normal water wave on the surface of a pond, the water molecules near the surface move in which direction?
Up and down only. In the direction of the wave motion. In completely random directions. They do not move at all. In the opposite direction to the wave motion.
The Earth's atmosphere is relatively transparent to
X-rays. ultraviolet light. radio waves. no types of electromagnetic waves. all types of electromagnetic waves.
Star A appears bluish in color, while Star B appears reddish in color. This tells you that
Star A is less luminous than star B. Star A is hotter than star B. Star A is more luminous than star B. Star A is cooler than star B. Star A must have the same luminosity as star B.
The frequency at which a star emits most of its light depends upon its
distance from us. luminosity. temperature. eccentricity. velocity toward or away from us.
Human bodies normally emit what kind of radiation?
Visible light. Infrared light. Ultraviolet light. Radio waves. Gamma rays.
The Sun has a temperature of 6000 K and its peak emission occurs at a wavelength of 4.8E-7 cm. What would be the wavelength of the peak emission from a star with a temperature of 12000 K?
4.8E-7 cm. 3.6E-7 cm. 9.6E-7 cm. 1.2E-7 cm. 2.4E-7 cm.
According to Kirchoff's laws, hot luminous solids emit what kind of spectra?
Continuous spectra. Emission spectra. Absorption spectra. Synchrotron spectra. This is a trick question. Solids do not emit radiation.
Each element has its own characteristic spectrum because
the speed of light differs for each element. some elements have higher temperatures than others. atoms combine to form molecules, releasing different wavelengths depending on the elements involved. electron energy levels are different for different elements. hot solids, such as tungsten, emit a continuous spectrum.
Rutgers is building an 11m optical telescope. Where is this telescope located?
Chile. Hoboken. Hawaii. Australia. South Africa.
Compared to a blue photon, a red photon has ________ wavelength and ________ speed.
longer; faster. longer; slower. longer; the same. shorter; the same. shorter; faster.
In the laboratory, I am looking at a hot glowing object through a tube than has some cool gas in it. I see
just a continuous spectrum. a continuous spectrum with some absorption lines. a continuous spectrum with some emission lines. a spectrum with only emission lines in it. no spectrum at all.
The visible (Balmer) series of hydrogen lines, when seen in absorption, is due to electrons
initially in the ground state. which make a transition to the ground state. initially in the second allowed orbit. which make a transition to the second allowed orbit. which do not move from the ground state.
At what time of night would you expect to see a full moon highest in the sky?
6 pm. 9 pm. Midnight. 3 am. 6 am.
The seasons on Earth occur primarily because the
Earth rotates on its axis. Earth's axis is tilted with respect to the ecliptic. Earth's distance from the Sun changes through the year. moon revolves around the Earth. Sun and Earth are moving through the Milky Way.
If a star rises at 8:30 pm tonight, then it will rise two months from now at
8:30 pm. 10:30 pm. 12:30 pm. 4:30 pm. 6:30 pm.
The point directly over an observer's head is her
nadir. zenith. south pole. horizon. great circle.
Eclipses do not occur each month because
the Moon is always in the ecliptic. the Moon's orbit is eccentric. the Moon's distance from the Earth is too large except during eclipse seasons. the Moon's orbital plane is inclined (tilted) to the ecliptic plane. the Moon's angular size is not equal to the Sun's at all times.
The diameter of Earth at its equator is about 12,800 km. What is this in scientific notation?
1.28E11 m. 1.28E7 m. 1.28E5 m. 1.28E9 m. 1.28E4 m.
Greek astronomers did not detect stellar parallax because
the Earth does not move. this would have violated Aristotelian physics. the stars are very far away. Copernicus was the first person to predict that parallax should be observed. they observed only retrograde motion.
In the heliocentric model of the solar system, retrograde motion occurs when
two planets pass each other in their orbits. two planets are farthest apart. two planets are on opposite sides of the Sun. one of the planets is nearest the Sun in its orbit. one of the planets is farthest from the Sun in its orbit.
Tycho Brahe's observations of the Sun, Moon, and planets were most important to astronomy because they
proved that the Sun orbited the Earth. allowed Kepler to discover his three Laws of Planetary Motion. proved that the Earth orbited the Sun. proved that Tycho's model of the solar system was correct. demonstrated the existence of stellar parallax.
To calculate your weight on the surface of a planet, you need to know your mass and
the surface gravity of the planet. the mass of the planet. the period and semi-major axis of the planet's orbit. the atmospheric surface pressure of the planet. the radius of the planet.
If the distance between two masses is increased by a factor of five, how does the gravitational force between them change?
It doesn't. The force remains the same. It increases by a factor of five. It increases by a factor of 25. It decreases by a factor of five. It decreases by a factor of 25.
According to Kepler, the planets travel around the Sun in
ellipses. parabolas. circles. hyperbolas. eclipses.
The planet Jupiter orbits the Sun with a semi-major axis of roughly 5 AU. Using Kepler's Third Law, estimate its orbital period.
about 1 year. about 25 years. about 3 years. about 9 years. about 11 years.
The Sun appears in a different constellation each month due to the
Earth's rotation on its axis. Earth's orbital motion around the Sun. Sun's motion in the Milky Way. motion of the constellations through the Milky Way. precession of Earth's rotation axis.
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