Chapters 3, 4, & 5 Flashcards
What is the geocentric model of the universe?
Belief that the Earth was the center of the universe.
Who came up with the idea of the geocentric model?
Greeks
What is the ptolemaic model?
The geocentric model of the universe developed by ptolemy in about 150 A.D.
What is prograde?
The usual movement of the planets from West to East.
What is retrograde?
The “drifting backwards” of the planets from East to West and back to East again.
What is an epicycle?
The individual rotation of a planet or body.
What is a deferent?
The larger circle in which a planet orbits around another planet or body.
What is the heliocentric universe?
Theory that the Sun is the center of the universe.
Who is Copernicus?
Scientist who introduced the idea of a heliocentric (sun centered) universe.
Who is Tycho Brahe?
Scientist who supported Copernicus’ theory of a heliocentric universe but thought that the sun revolved around the earth while the other planets revolved around the sun.
Who is Johannes Kepler?
Scientist who worked under Tycho Brahe for some amount of time and eventually abandoned Tycho Brahe’s original idea of the sun going around the earth and the other planets going around the sun and developed the sun-centered elliptical model.
What is an ellipse?
A ovular shape, not a circle.
- Moderately to highly eccentric
- 2 centers and 2 foci
- 2 radii (1 radius=major axis and 1 radius=semi major axis)
What is Kepler’s first law of planetary motion?
With the sun at one foci, planets go around in elliptical orbits.
What is Kepler’s second law of planetary motion?
Planets sweep equal areas in equal intervals of time (planets closer to the Sun move faster).
What is Kepler’s third law of planetary motion?
The period of a planet is related to the distance to the planet by the equation P2=a3 (harmonic law).
What is an aphelion?
The point at which an object orbiting the Sun is farthest from the Sun.
What is perihelion?
The point at which an object orbiting the Sun is closest to the Sun.
Who was Galileo?
Philosopher and The father of Physics; created the first telescope and discovered tht the mooon is barren. Also discovered Jupiter has many moons.
How did Africans use the orientation of the moon to predict rainfall?
They observed and discovered that the orientation of the “horns” of a crescent moon is relative to the horizon and is closely tied to local rainfall patterns.
Describe the importance of the Egyptian obelisk and Stonehenge in England.
The obelisk was used to tell time and the stone henge was used to make the seasons.
Who suggested the geocentric model of the universe?
Greeks
What is Copernicus’ theory?
- That the sun was the center of the universe.
- The distance between earth and the other planets and the speed of Earths rotation makes other planets appear to go “backwards” in an infinity shape.
What is the harmonic law of planetary motion and how is it used today in interplanetary travel?
The harmonic law states that a period of a planet is relative to the distance to the planet by the equation P2=a3. Scientist use this law to determine how long it will take to travel to a given planet at a given time.
What are the three parameters necessary to descibe motion of a body in detail?
Speed, Velocity, and Acceleration
What is speed?
The rate of change of distance with time.
(Ex. 20 km/h)
What is velocity?
The rate of change of displacement with respect to time, with direction specified.
What is acceleration?
The rate of change of velocity with time (How fast is fast?).
What is the difference between speed and velocity?
Velocity specifies the direction in which an object is traveling, speed does not require it.
What is the equation for speed?
Distance/Time.
What is the equation for velocity?
Distance/Time with direction specified.
What is the equation for acceleration?
Velocity/Time = Vf-Vi divided by T (V final minus V initial divided by time.
What is momentum?
The product of an object’s mass and velocity
What is force?
A push or pull
What is the difference between mass and weight?
Mass is the amount of “stuff” in an object and weight is the fve on the mass of an object by gravity of the Earth.
What is the relationship between free fall and weightlessness?
Free fall is when an object is falling without resistance and objects in free fall are said to be “weightless”
What is Newton’s first law of motion?
An object in motion will stay in motion unless another outside force acts upon it.
(Ex. If you press the brake on a car while it is moving it will stop.)
What is Newton’s Second Law of Motion?
If a force is acted upon an object, the object will accelerate faster/slower depedning to the mass.
(Ex. A weight ball thrown in the air with the same force as a regular basket ball will go a shorter distance because it’s mass is greater than the basketbal.)
What is Newton’s Third law of Motion?
For every action, there is an equal and opposite reaction.
(Ex. Rockets)
What is angular momentum?
The momentum attributed to rotation or revolution.
Equation: m x v x r (r= radius)
What are the three types of energy found in the book?
Potential, Kinetic, and Radiative
What is the difference between heat and temperature?
Heat is a form of energy, temperature is the measurement of heat.
What are the three temperature scales used to day and which is most used by scientists?
Farenheit, Celcius, and Kelvin; Scientists use Kelvin.
What is the universal law of gravitation?
The law expressing the force of gravity between two objects.
What is inverse square law?
Force between two objects = G x Mass of 1 object x Mass of another object/ Distance between 2 objects squared
What is a tidal force?
A force caused when the gravity pulling on one side is greater than the gravity pulling on the other side, causing the object to stretch.
What is a spring tide?
Higher than average tides that occur at the new and full moon, when the tidal forces from the Sun and Moon both act along the same line. (BOTH SUN AND MOON ON SAME SIDE)
What is a neap tide?
Lower than average tides on Earth that occur at first and third quarter moons when tidal forces from the Moon and Sun oppose one another pulling the water in a diagonal direction.
What is the correct order of the colors in the rainbow?
VIBGYOR
What is refraction of light?
When one part of the light gets reflected and the other absorbed into an object.
What is reflection of light?
When a light is completely reflected and none of it is absorbed.
What is the speed of light?
3x108 m/s
What is wavelength?
The distance from the crest to crest or trough to trough
What is the frequency of a wave?
How many waves occur per second.
What is a packet of energy called?
Photon.
What is the energy of the wave packet called?
Quanta
How do you calculate the energy of a wave packet?
E = h x F (Energy equals Planck’s constant times frequency)
What is the wavelength of the color Violet?
400 x 10-9m
What is the wavelength of the color red?
700 x 10-9 m
