Exam 1 Flashcards
What is the cosmic address?
Earth
Solar System
Milky Way
Local Group
Local Supercluster
Universe
What is a lightyear?
The distance light travels in one year
What is an Astronomical Unit?
The average distance between Earth and the Sun
Age of the universe
14 billion years
Age of the solar system
4.5 billion years
The Big Bang
The event thought to mark the birth of the universe
The early universe only contained what elements?
Hydrogen and helium
Most galaxies are moving _____ us.
away from
The farther away a galaxy is the _____ it is moving.
faster
What is the result of Hubble’s observations?
What does it show the universe doing?
The universe is expanding
What is the raisin cake analogy?
As a raisin cake expands, every raisin moves away from every other raisin, just as galaxies move away from each other in an expanding universe.
What is mass?
The amount of matter an object has
What is weight?
The amount of force that acts on an object
What causes weightlessness?
Falling without any resistance to slow you down (free-fall)
Newtons Laws of Motion
- An object moves at a constant velocity if there is no net force acting on it.
- force = mass x acceleration (F = ma)
- For any force, there is always an equal and opposite reaction force.
Universal Law of Gravity
- Every mass attracts every other mass through gravity.
- The strength of the gravitational force attracting any two objects is directly proportional to the product of their masses.
- The strength of gravity between two objects decreases with the square of the distance between their centers.
Fg=G(M1M2/d^2)