Astronomy Test 2 - History, Light, Telescopes ctr 2/19/03

Please put your name on the BACK of the last sheet only, near the staple.

Matching - Place the number corresponding to the best answer in the blank provided. Some answers may be used more than once. 2 points each.

___ Craters on the moon 1-Copernicus
___ Law of universal gravitation 2-Tycho
___ First used the telescope on the heavens 3-Galileo
___ Three laws of planetary motion 4-Newton
___ Heliocentric model of universe 5-Kepler
___ Geocentric model of universe 6-Ptolemy
___ Greatest Genius
___ Best naked eye observer
___ Discovered moons of Jupiter
___ Used Tycho's data

Multiple choice - Place the number corresponding to the best answer in the blank provided. Answer all. Good luck!

___ How will you be able to tell the difference between science and pseudo-science?
1-Read science news from reputable sources, such as Science or Nature.
2-Take science classes, learn the basics of science and statistics, and learn how to ask the best questions.
3-Always consider the source of your information.
4-All of the other answers (and more!)

___ The temperature scale that starts with absolute zero as 0 is called

___ The atomic number of an atom indicates the number of
4-particles in the nucleus.

___ An atom which has 4 protons and 6 neutrons will be electrically neutral if it contains
1-10 electrons.
2-at least one electron.
3-6 electrons.
4-4 electrons.

___ When our Sun converts hydrogen into helium, the leftover mass is converted to energy. Which equation below best describes this process?
2-E=1/2 mv2
4-eV=1.60X10-19 J

___ The downward force of gravity acting on your body is your
1-acceleration of gravity.

___ Galileo challenged the idea that objects in the heavens were perfect by
1-showing that our Sun is covered with sunspots.
2-inventing the telescope.
3-showing heavy objects fall at the same rate as lighter objects.
4-proving Kepler's laws were correct.

___ When considering light as small packets of energy, scientists call these
3-gamma rays.

___ Which does not belong?
1-Gamma rays
2-Red light
3-Blue photons
4-Sound waves

___ The Doppler effect implies that a galaxy that is moving away from Earth would have a spectrum that is

___ Compared to our own yellow Sun, the bright blue star in the constellation of Orion, Rigel, must be

___ The ability to see make things appear larger is called

___ Telescopes created with glass mirrors are called

___ An orbiting telescope works better than one on the ground because
1-it is closer to the stars
2-it is in the dark all the time
3-it doesn't have to look through the air
4-it has no chromatic aberration

___ Light from a distant star can be divided into a spectrum by using a glass prism or
1-diffraction grating.
2-adaptive optics.
3-radio telescope.

___ Firefighters are able to determine the temperature of a fire from great distances using a device called a pirometer. In order to calculate the fire temperature, this device probably measures
1-wavelengths of photons emitted by the fire.
2-the characteristics of the material fueling the fire.
3-the absorption of photons by cooler gas surrounding the fire.
4-an electrical current caused by electrons moving in the fire.

___ Observing an astronomical target, an astronomer measures a wavelength shift between the central wavelength of the observed emission line and the wavelength of that line as seen in a laboratory at rest. What can he infer from the line shift?
1-The velocity of the target with respect to the astronomer.
2-The age of the target.
3-The elemental abundance of the target.

___ An astronaut weighs 160 lbs and has a mass of 72 kg when standing in Kansas City. What will the astronaut's weight and mass be when in outer space, far from other planets or stars?
1-W = 0 lbs and M = 0 kg
2-W = 160 lbs and M = 0 kg
3-W = 0 lbs and M = 72 kg
4-W = 160 lbs and M = 72 kg

___ Galileo's observations of Jupiter showed that
1-Earth orbits our Sun.
2-Jupiter has rings just like Saturn.
3-Earth is not the center of all orbits.
4-it goes through phases much like our Moon.

___ The energy attributed to an object by virtue of its motion is known as
1-potential energy.
2-kinetic energy.
3-radiative energy.
4-mass energy.

___ When the returning Space Shuttle enters the atmosphere and begins to slow down, its kinetic energy is primarily converted into
2-thermal energy.
3-potential energy.
4-reverse thrust.

___ The most important specification of a telescope is its
2-focal length
3-type - reflector or refractor
4-objective diameter

Short answer - 6 points each

1. A telescope has an objective with a focal length of 2000 mm. If it is used with an eyepiece of 20 mm focal length, what is its magnification?

2. Draw and label a Newtonian telescope, showing the light path through the telescope.

3. Why did Galileo prefer Copernicus's model of the solar system to that of Ptolemy?

4. (a) Why do radio telescopes have inherently poor resolution?

(b) How can using a second radio telescope improve the resolution?

5. A box of candy weighs 1 lb on the surface of the earth, 4000 mi from its center. What would it weigh at the top of a ladder 8000 mi from the center of the earth?

6. Explain with a diagram what causes tides.