gravity
numbers
Sir Isaac You-Know-Who
satellites
orbits
100
"falling around the Earth"
What is satellite motion?
100
8 km/hr
What is the minimum speed for an object to become an Earth satellite?
100
F = (Gm1m2)/r^2
What the Universal Law of Gravity?
100
"falling around the Earth"
What is satellite motion?
100
geosynchronous
What is a circular orbit over the equator with a period of 24 hours. It remains pointed at the same point over Earth and from an Earth perspective, does not appear to move.
200
Where do you weigh more - the bottom of Death Valley or the top of a mountain?
the bottom of Death Valley
200
If our sun collapsed into a black hole (not likely), what would happen to the Earth's orbit?
NOTHING. The mass of the sun would not change. It would just become more concentrated and the pull of gravity on Earth would remain the same!
200
F = m a
What is Newton's Second Law of Motion?
200
The moon, GeoSat, and Sputnik.
What are examples of satellites?
200
For orbits of greater altitude, is the period longer or shorter?
Longer
300
How does the force of gravity change between two bodies when the distance between them is doubled?
The force of gravity decreases by 1/4
300
11.2 km/s
What is the minimum speed for a satellite to escape Earth's gravitation speed? (escape speed)
300
If your weight doubled since you were ten years old, how much more does Earth's gravity pull on you?
What is "twice as much?"
300
This is why we launch our satellites above Earth's atmosphere.
What is "to avoid air friction?"
300
When is the total energy of a satellite greater, at the apogee or perigee?
NEITHER! Total energy remains constant, but kinetic (KE) goes up near perigee as potential (PE) goes down. Together KE + PE = constant. They just trade off.
400
What is the strength of the gravitational acceleration at the center of Earth?
What is zip, nada, ZERO!
400
6.67 X 10^-11
What is the gravitational constant of our universe?
400
What are the names of the closest and farthest points on an elliptical orbit?
What are perigee and apogee?
400
Why is kinetic energy a constant for a stalellite in circular orbit but not for a satellite in an elliptical orbit.
For a satellite in circular orbit, no component of force acts along the direction of motion causing the speed, and thus the KE, to not change. In an elliptical orbit, a component of force exists along the direction of the satellite's motion due to gravity's pull. This component changes the speed and thus the KE.
500
Is "weightlessness" the absence of gravity? If yes, explain where you can find that in the universe and if no, explain why not.
NO! Gravity never goes away. It only gets weaker with distance. "Weightlessness" is just an absence of a support force (like when all objects are falling together).
500
How is the force of gravity related to the distance between objects?
The force is proportional to the square of the distance between.
500
What was Newton's big idea about the motion of the moon?
That it is a projectile and is "falling around the Earth."
500
Why doesn't the force of gravity change the speed of a satellite in circular orbit?
Gravity always pulls perpendicular to the path of motion (radially inward) so there is no component of the gravitational force acting in the direction of travel.
500
What did Kepler discover about the periods of planets and their distances from the sun?
The square of the orbital period is directly proportional to the cube of the planet's average distance from the sun.
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