# Physical Science

Topics: Orbit, Moon, Gravitation Pages: 4 (881 words) Published: July 12, 2010
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Quiz 7
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Please Note: It is recommended that you save your response as you complete each question.|

Question 1| | (1 point)Save|
Compared to the gravity at Earth’s surface, Earth’s gravity at a distance twice as far from Earth’s center is | a)| one half as much|
| b)| one fourth as much|
| c)| one sixteenth as much|
| d)| zero|
Question 2| | (1 point)Save|
The potential energy of a satellite in a circular orbit is
| a)| the same everywhere|
| b)| greatest at the apogee (farthest point)|
| c)| greatest at perigee (nearest point)|
| d)| the same as its kinetic energy|
Question 3| | (1 point)Save|
A communications satellite that orbits at a fixed part of the sky | a)| travels at a speed of 8 km/s|
| b)| takes 24 hours to complete each orbit|
| c)| travels at a speed slightly greater than 8 km/s|
| d)| has zero orbital speed and doesn’t move|
Question 4| | (1 point)Save|
A spacecraft on its way from Earth to the Moon is pulled equally by Earth and Moon when it is | a)| closer to the Earth’s surface|
| b)| closer to the Moon’s surface|
| c)| halfway from Earth to Moon|
| d)| at no point, since Earth always pulls more strongly| Question 5| | (1 point)Save|
When a projectile achieves escape speed from Earth, it
| a)| outruns the influence of gravity, but is never beyond it| | b)| forever leaves Earth’s gravitational field|
| c)| comes to an eventual stop, eventually returning to Earth at some future time| | d)| likely becomes a black hole|
Question 6| | (1 point)Save|
A ball rolling along a bowling alley maintains its speed because | a)| it has inertia|
| b)| gravity doesn’t pull on it while moving|
| c)| there is no horizontal force acting on the ball|
| d)| it behaves as a projectile|
Question 7| |...