Name:    Einstein's Universe Exam1

True/False [Each question is worth 1 point]
Indicate whether the sentence or statement is true or false.

1.

Copernicus was one of the first to propose that Earth moved around the sun.

2.

The apparent positions of stars around the sun during an eclipse have been used to prove the general theory of relativity.

3.

A kilometer contains 1 million meters.

4.

Changing the direction of a moving body does not change its velocity.

5.

The Copernican model of the solar system has the planets orbit the sun along elliptical paths.

6.

Galileo used a telescope to observe the phases of Jupiter.

7.

Galileo developed three theories of motion that became laws of motion when Newton proved Galileo's theories correct.

8.

The Ptolemaic model of the universe was heliocentric.

Numeric Response [Each question is worth 1 point]

9.

Suppose Einstein is moving past you at a speed of 0.9c. While 1 hour passes for you, how much time passes for Einstein?  [Note, you are stationary with respect to Albert].

10.

A cricket ball has a rest mass of 1 kg. Eisntein throws the cricket ball at you at a speed of .9999c. What is the mass of the cricket ball at that speed? [Note, you are stationary with respect to Albert].

11.

You see Einstein moving away from you at 0.9c. He turns on a lamp that is pointing back toward you. How fast do you measure the light from the lamp to be moving? [Note, you are stationary with respect to Albert].

12.

Suppose Einstein is moving past you at a speed of 0.99c. Because his spaceship is the same model as yours, you know that it is 100 meters long when it is at rest. How long is his spaceship as it moves by you?  [Note, you are stationary with respect to Albert].

Multiple Choice
Identify the letter of the choice that best completes the statement or answers the question.

13.

According to the theory of general relativity, gravity is caused by
 a. the equivalence principle. b. the change in mass of a moving body. c. the constant speed of light. d. the curvature of space-time. e. none of the above

14.

Ptolemy's model of the universe
 a. was heliocentric. b. contained epicycles. c. included elliptical orbits. d. all of the above e. none of the above

15.

Which of the following was not included in Copernicus’s Heliocentric Model
 a. Inferior planet orbits are larger b. Earth orbits like any other planet c. The Sun is at the center d. Retrograde motion occurs when we “lap” Mars and other superior planets

16.

Which of the following people did not accept a heliocentric model for the universe?
 a. Galileo b. Copernicus c. Tycho d. Newton e. Kepler

17.

The book "De Revolutionibus Orbium Coelestium"
 a. is a dialog written to convince the general public of the merits of the Copernican theory. b. first described the Copernican theory. c. describes the Tychonian theory. d. describes how Galileo's observations and Kepler's calculations proved the Copernican theory. e. describes the construction of Galileo's telescope and his observations.

18.

Galileo found that
 a. only objects made of earth and water fell to the ground. b. heavy and light objects fall at the same rate. c. heavy objects fall faster than lighter objects. d. the moon's orbit is elliptical. e. falling objects fall at a constant speed.

19.

4.4106 divided by 8.81010 is equal to
 a. 3.91017. b. 5.010-4. c. 3.91016. d. 5.010-5. e. 5.0104.

20.

The equivalence principle can be illustrated by
 a. the change in mass of a moving body. b. the formation of energy by nuclear fusion. c. a space capsule coasting through space at constant velocity. d. a person riding in an elevator. e. the increase in the speed of light from a star as the light moves past the sun during a solar eclipse.

21.

If the nearest star is 4.2 light-years away, then
 a. the star must be very young. b. the star must have formed 4.2 billion years ago. c. the light we see left the star 4.2 years ago. d. the star must be very old. e. the star is 4.2 million AU away.

22.

The second postulate of special relativity states that
 a. the laws of physics are the same for all observers, no matter what their motion, as long as they are not accelerating. b. the speed of light is constant and will be the same for all observers independent of their motion relative to the light source. c. observers cannot detect their uniform motion except relative to other objects. d. observers cannot distinguish locally between inertial forces due to acceleration and uniform gravitational forces due to the presence of a massive body. e. the acceleration of an object is proportional to the applied force and inversely proportional to its mass.

23.

The Copernican system was no more accurate than the Ptolemaic system in predicting the positions of the planets because
 a. Copernicus used inaccurate data from Ptolemy's system. b. the Copernican system used the old value for the radius of Earth. c. in the Copernican system only Mercury and Venus orbit the sun, all other planets orbited Earth. d. the Copernican system included uniform circular motion. e. Copernicus had been unable to detect parallax.

24.

Galileo's telescopic discovery of moons orbiting Jupiter was important because it showed that
 a. the universe could contain centers of motion other than Earth. b. Earth might move along an orbit and not leave the moon behind. c. Jupiter was much more massive than Earth. d. all of the above e. a and b above

25.

3.0105 times 1.5109 is equal to
 a. 2.01045. b. 4.51045. c. 2.01014. d. 2.0104. e. 4.51014.

26.

If light takes 8 minutes to reach Earth from the sun and 5.3 hours to reach Pluto, what is the approximate distance from the sun to Pluto?
 a. 5.3 AU b. 40 ly c. 40 AU d. 5.3 ly e. 0.6 ly

27.

Galileo's observations of the gibbous phase of Venus proved
 a. that all of the planets orbited the sun. b. that Venus orbited the sun. c. that the moon orbited Earth. d. that Earth orbited the sun. e. that Venus had an atmosphere.

28.

Due to the curvature of space-time by the sun, light from stars that passes near the edge of the sun will
 a. be focused so that the stars appear brighter than if space-time was not curved. b. be bent so that the stars are no longer visible. c. be bent so that the stars appear further from the edge of the sun than if space-time was not curved. d. not be affected by the curvature of space-time. e. be bent so that the stars appear closer to the edge of the sun than if space-time was not curved.

29.

Galileo's telescopic discoveries of mountains on the moon and spots on the sun were controversial because they suggested that the sun and moon
 a. were not perfect. b. orbited each other. c. were inhabited. d. did not orbit Earth. e. were the same kind of object.

30.

Tycho Brahe's greatest contribution to astronomy was
 a. his model of the universe. b. his telescopic observations. c. his discovery of three laws of motion. d. his years of careful observations of the planets. e. a and b above

31.

One of the first tests of the general theory of relativity was
 a. the demonstration of a hammer and a feather falling at the same rate on the moon. b. the determination of the speed of light to be constant. c. the determination of the rate of advance of the perihelion of Mercury's orbit. d. the description of the orbit of the moon. e. the change in mass of a particle moving at a high speed.

32.

If the light takes 8 minutes to reach Earth from the sun and the nearest star is 4.7 ly from the sun, what is the distance from the sun to the nearest star in astronomical units?
 a. 1.51011 AU b. 1.7 AU c. 310,000 AU d. 214 AU e. 37.6 AU

Calculation

33.

Answer the following questions, giving as much detail as possible. Remember to show all the work necessary to arrive at the correct solution. Partial credit will be given as applicable. Note: be sure to label your answer with the correct units. (5 points).

a ) Use the following data to determine the force of gravity the Moon exerts on the Earth.

b) What is the force of gravity that the Earth exerts on the Moon?

34.

Match each of the scientists in the left column with the short description in the right column:

i.      Kepler______      a) his observations supported the heliocentric                                                 theory and showed that Aristotle and Ptolemy                                           didn’t know everything

ii.      Galileo______      b) developed the original form of the modern                                                 heliocentric theory

iii.      Newton_____      c) provided the data that lead to the                                                       development of the laws of planetary motion

iv.      Copernicus__      d) worked out laws of gravity and motion

v.      Brahe______      e) studied earlier observations and discovered                                           three laws of planetary motion

Complete each sentence or statement. [Each question is worth 1 point]

35.

The _______________ states that an observer cannot distinguish locally the difference between inertial forces due to acceleration and uniform gravitational forces due to the presence of a massive object.

36.

What is the speed of light in meters per second?

37.

The first observations of objects in the solar system that orbited neither the sun nor Earth were made by _______________.

38.

Light takes about 8 minutes to travel from the sun to Earth and about 40 minutes to travel from the sun to Jupiter. Jupiter is about _______________ AU from the sun

39.

The _______________ of a particle is the mass we would measure if the particle were not moving.

40.

A ball is dropped from the top of a science building. What is the speed of the ball after falling for three seconds?

41.

The number 52,600,000,000 would be written in scientific notation as _______________.

42.

“All natural motion is circular” was an idea  first put forward by_____________.