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## Ignore words

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Spring Tide
When there is a new moon, making the higher tides higher and the lower tides lower. The moon, earth and sun are all alined
Neap Tide
When the moon is at the first or third quarter, and there are lower high tides and higher low tides
Law of Universal Gravitation
a force of gravity that's acts on all objects in the universe
How Newton Used Data To Develop this Law
Newton saw that apples fall at about 4.9 meters per se…
g=GM/r squared
How can you find g on a planet?
acceleration due to gravity halfway to the center of the earth
On earth acceleration due to gravity is 9.8, but when halfway to the center of the earth, you divide by 2 so it would be 4.9
How is weight related to the force of gravity?
Weight is equal to the amount of gravitational force that exists between the object and the earth
What is Apparent weightlessness?
In free fall, when an object has the lack of a support force, and therefore feels like it is weightless
How do satellites work?
Satellites are projectiles that are "falling" around the earth both horizontally and vertically
Geosynchronous Satellite
A satellite that completes one revolution of the earth in a period of 24 hours. (ex. GPS system)
How does speed of a satellite relate to the distance it is from the earth?
The closer a satellite orbits the earth, the greater the speed it travels at. This is because it is closer and has a stronger gravitational pull.
Circular vs. Elliptical Orbit
A circular orbit is when an object travels in a circular path, an elliptical orbit is when a planet/satellite orbits in an oval shape
Gravitational field
a force field that exists in the space around every mass or group of masses
76-86 years
How often does halley's comet pass earth?
Full Moon
When the Earth, Moon and Sun are in a line and there is high tide
New Moon
When the Moon, Earth and Sun are in a line and there is low tide
Solar Day
24 hour long day and has everything rotate 1 time under the sun
Lunar Day
24 hours and 15 mins. day and is the time it takes for the Earth to orbit under the Moon
Eccentric Orbit
The foci are very wide apart and the orbit is very long and almost straight (Earth's orbit is not eccentric)
Star Exists by?
Stars exist through the process of thermonuclear fusion. Star must have hydrogen and gravitation
Black Hole
A star that is at least 4 times the size of the sun and all of its hydrogen turns into helium. Thermonuclear fusion is the hydrogen in a star and when it runs out gra…
v squared=GM/r
Orbital Speed for any satellite around a heavenly body
momentum
(p) vector quantity describing the quantity of motion or inertia in motion. Recognizes that both mass and velocity have a part in the motion of an object and is proportional to both (is zero …
kinetic energy
a running dog
elastic collision
No kinetic energy is lost in particle collisions
inelastic collision
A collision in which the colliding objects become distorted, generate heat, and possibly stick together.
Law of Conservation of Momentum
If no external forces act on a system, then the total momentum of that system remains the same