Universal Gravitation Review Set

5.38 x 10^15 + 7.14 x 10^13

5.4514 10^15

4.35 x 10^7 + 2.38 x 10^8

. 2815 x 10^8

8.89 x 10^-22 x 2.27 x 10^-23

20.1803 10^-1

6.29 x 10^7 x 3.12 x 10^5

19.6248 x 10^12

When an astronaut in orbit is weightless, he or she is a.beyond the pull of Earth's gravity. b.still in the pull of Earth's gravity. c.in the pull of interstellar gravity. d.beyond the pull of the sun's gravity.

b

Compared to the gravitational field of Earth at its surface, Earth's gravitational field at a distance three times as far from Earth's center is about a.one third as much. b.one half as much. c.one ninth as much. d.zero.

c

Consider a space probe three times as far from Earth's center. Compared at Earth's surface, its gravitational attraction to Earth at this distance is about a.one third as much. b.one half as much. c.one ninth as much. d.zero.

c

The moon falls toward Earth in the sense that it falls a.with an acceleration of 10 m/s2, as apples fall on Earth. b.with an acceleration greater than 10 m/s2. c.beneath the straight-line path it would take without gravity. d.above the straight-line path it would take without gravity.

c

Newton did not discover gravity, for early humans discovered it whenever they fell. What Newton did discover is that gravity a.tells us about why the universe expands. b.tells us how to discover new planets. c.accounts for the existence of black holes. d.extends throughout the universe.

d

Newton's law of universal gravitation had a great impact on society as many scientists, artists, writers, and philosophers hoped that a.more complex and universal laws would explain other phenomena of the world. b.greater observations would require fewer experimentations. c.no further explanation of other phenomena of the world would be required. d.studying other phenomena of the world would lead to just as simple and universal laws.

d

A black hole is a.simply a collapsed star. b.a two-dimensional surface in space. c.barely visible with high-powered telescopes. d.a new form of gravity.

a

Compared to the gravitational field of Earth at its surface, Earth's gravitational field at Earth's center is a.zero. b.half as much. c.twice as much. d.three times as much.

a

Newton determined that the pull of Earth's gravity caused both apples and a.the moon to fall toward Earth. b.the moon to move away from Earth. c.the sun to move away from Earth. d.stars to fall toward Earth.

a

Planets remain in orbit while falling around the sun due to their a.tangential velocities. b.zero tangential velocities. c.accelerations of about 10 m/s2. d.centrifugal forces that keep them up.

a

The highest ocean tides occur when the Earth and moon are a.lined up with the sun. b.at right angles to the sun. c.at any angle to the sun. d.lined up during spring.

a