Orbits and Gravity Review

Physics 1A

What is Keplers First Law?

The orbits of the planets are ellipses with the sun at one focus (Law of Ellipses)

What is Keplers Second Law?

A line connecting a planet to the sun will sweep out equal areas in equal time intervals (Law of Equal Areas)

What is Keplers Third Law?

The square of a planet’s orbital period is proportional to the cube of its average distance from the sun  (T²∝r³) (Law of Periods)

Define Geocentric

Earths at the center of the universe

Define Heliocentric

Sun is at the center of the universe

Define Retrograde motion

The apparent backward motion of a celestial body as viewed from Earth, caused by the relative of Earth and the body orbiting the sun

Define Eccentricity

high when its an ellipse and low when its a circle

Define Aphelion

Point in orbit an object is farthest from the sun & moving its slowest

Define Perihelion

Point in orbit an object is closest to the sun & moving its fastest

Define Period

Time to go around once