# Astronomy first test

Explain the difference between Astronomy and Astrology
Astronomy is the study of the universe while Astrology is a belief system that includes the idea that stars can tell events in your life.
What’s the difference between mass and weight?
Mass is the amount of matter in someone while weight is the gravity force the person has somewhere.
What is an astronomical unit or 1 au?
The distance from the earth to the sun.
Will things on earth ever fall at different rates?
Gravity is the same for all things on earth but other forces such a wind or air resistance can change how an object falls.
What evidence did Galileo have to support the heliocentric model?
Knowing that the moons of Jupiter were orbiting that planet and that Venus has different phases because it’s orbiting the sun as well.
What’s the difference between a hypothesis and a theory?
A hypothesis is a proposed scientific explanation for a set of observations while a theory is a well tested and supported explanation.
How did Newton describe gravity?
As a force that moves a mass in a straight line
Describe main parts of the Geocentric model
Made by Ptolemy where everything revolves around the earth. Model of the solar system that predicted positions of planets for any date and time.
What planet did Kepler use to develop his laws of planetary motion?
Mars
What is Inertia?
Tendency of a moving object to continue Ina straight line or a stationary object to remain in place.
How does a planet’s speed change as it moves around the sun?
The closer the planet is to the sun, the faster it’s speed and the farther it is from the sun, the slower the speed.
What would happen to Earth of inertia stopped?
Gravity would take over and earth would fall into the sun.
In what ways is the heliocentric model different from the geocentric?
The heliocentric model includes the planets revolving around the sun while the geocentric model has everything revolving around the Earth.
What would happen if the sun had no gravity?
Inertia takes over and the earth would fly away in a straight line.
Describe the motion of orbit
Planets revolve around the sun at varying speeds.
What two factors determine determine the gravitational force?
Mass and distance
In Einstein’s view how does mass affect space?
Mass curves space time.
Who developed the geocentric model of the solar system?
Ptolemy
Describe the shape of a planet’s orbit
Ellipse (oval)
How does the heliocentric model explain the daily and yearly motion of the sun and stars?
The sun moves around in its own small space and the stars move depending on where the earth is compared to the sun.
What is Newton’s second law of motion? Give an example
F=ma. Ex: the bigger the mass the less force needed and the more it accelerates.
What do we call the speed necessary to leave Earth?
Escape velocity.
What force causes everyday objects to slow down with what appears to be no outside force?
Friction
What is a light year?
The distance light travels in a year.
What do we call friction from the air?
Air resistance
How did Einstein revise Newton’s view of gravity?
Gravity results by curving space with mass.
What evidence did Aristotle have that the Earth was round?
During lunar eclipse the shape of earths shadow on the moon was round. All other planets are round. Coriolis effect
What affect does the speed of light and distances in space have on the light we see?
The light we see was made by a star many years before we actually see it making it ancient history
Who developed the heliocentric model of the solar system?
Capernicus
What is Newton’s third law of motion? Give an example of it at work
Action = reaction. Ex: two ppl pudding of each other on skateboards
What is the definition of astronomy?
The study of the universe
How does space affect light?
It can curve it if it passes by a large mass or star
The daily motion of the stars comes from? And the annual motion from?
Earth spinning. Moving around the sun.
Why do planets orbit? (2 factors)
Inertia and gravity
What is scientific notation?
Numbers made smaller or bigger in the form of a*10b
How do up thrust and air resistance work?
Upthrust counteracts the effect of gravity (reaction force of water) and air resistance pushes against whatever’s moving. The force that allows thins to fall slowly.
Tycho Brahe was the first to see what?
A supernova
Define cosmology
Our concept of the structure and origin of our universe
Give examples of ways we’ve benefited from Astronomy
Medical instruments, athletic shoes, portable coolers, virtual reality, sports training
Define science
An organized way of using evidence to learn about the world around us.
Categories: Astronomy