Chapter 2 Astronomy

Newton’s First Law A body continues in a state of rest or uniform motion in a straight line unless made to change by a force

Newton’s Universal Law of Gravitation Every mass exerts an attractive force on every other mass. This is based on their masses and distances Ex: weight; force of Earth on moon; Sun on Earth

Orbital Motion and gravity Balance between velocity (horizontal) and force (gravity) always down maintains orbit Perpendicular Space shuttle

Where F is net (total) Force m is mass Newton’s 2nd Law F=ma Where F is net (total) Force m is mass a is acceleration (change in velocity{speed})

Gravity is the single largest factor that has determined the state of our Universe since the Big Bang (expansion) & what it will look like in the future.

Circular motion A force is necessary to maintain circular motion For planets it’s the gravitational force.

Change in velocity(speed with direction) acceleration Change in velocity(speed with direction) Can be slow down or speed up or direction

For circular motion the Force & acceleration are always toward the center and perpendicular to the velocity.

When 2 bodies interact they create equal and opposite forces Newton’s 3rd Law When 2 bodies interact they create equal and opposite forces