Astronomy Chapter 3

Front 1

derive

Back 1

in common languag, this word means to obtain something, oten a chemical substance, from a specific source. AStronomers, mathematiciams, and physicists all use this word to mean deducing a conclusion logically (or mathematically) from a set of starting principles

Front 2

Inertia

Back 2

in common language, we might think of inertia as a tendency to remain motionless. Astronomers and physicists think more generally of inertia as the tendency of matter to resist a change in motion - of an object at rest to remain at rest, and of a moving object to remain in motion.

Front 3

force

Back 3

in common language, the word force has many meanings. Astronomers specifically mean a push and a pull.

Front 4

uniform

Back 4

here, astronomers mean that neither the speed nor the direction of travel changes

Front 5

weight

Back 5

in common language, we often use weight and mass interchangeable. Astronomers use mass to refer to the amount of stuff in an object, and weight to refer to the force exerted on that object by planets gravitational pull. your weight changes with location, but your mass stays the same no matter what planet you are on.