Kepler's Laws and Solar system

What is gravity?

• a force between objects that pushes them apart
• a force between any two objects that pulls them together
• a force that causes objects to remain at rest
• potato salad

This diagram shows the ___ system, first thought by Copernicus & supported by Kepler & Galileo.

• Heliocentric
• Ptolemaic
• Geocentric
• Polycentric

Because the earth revolves around the sun on a tilted axis...

• we have seasons
• we see different constellations in the sky different times of year
• the vertical ray of the sun travels from 23.5N to 23.5S
• All of the above

Kepler determined that the shape of a planets orbit around the sun is

• a circle
• an ellipse
• an eclipse
• a oblate spheroid

The force of attraction between objects that have mass.

• Force
• Gravity
• Weight
• Density

How does changing the distance between objects affect the force of gravity?

• Decreasing distance increases gravity
• increasing distance increases gravity 
• Distance does not affect gravity

From the choices below. Which of the following would you have the MOST WEIGHT?

• Europa

• Saturn

• Earth

• Ganymede

Shorter revolutions

• Inner planets
• Outer planets
• Both
• Neptune

What takes a year?

• rotation
• revolution

He discovered that the orbits of planets are ellipses. 

• A) Tycho Brahe 
• B) Copernicus 
• C) Kepler 
• D) Galileo