Solar System & Astronomy Basics
Light, Reflection, and Orbits
Archimedes, Buoyancy, and Levers
Simple Machines & Mechanical Advantage
Ancient Measurement & Observation
100

What does it mean when a system is described as "heliocentric"?

the sun is at the center

100

If a light beam strikes a flat mirror and forms a 43-degree angle with it, what is the angle between the mirror and the reflected ray?

43 degrees (The Law of Reflection says the angles must be equal.)

100

How would you explain Archimedes’ Principle?

Water pushes up with a force equal to the weight of the water that the object had to move in order to sink.

100

When lifting a heavy load using a lever, should the stationary point be placed near the load or near your grip?

close to the heavy object

100

True or false: Eratosthenes lived circa 200 BC, believing the earth to be spherical.

True

200

Which solar model is supported by evidence: one that places Earth at the center, or one with the sun at the center?

sun at the center (heliocentric)

200

True or false: The Law of Reflection ensures the angle of reflection always matches regardless of the type of light involved.

False (It has to be a smooth surface.)

200

If a 50-pound object sinks in water after displacing 40 pounds of water, what apparent weight would it have when submerged?

10 pounds (Archimedes’ Principle says the water will push up with a force of 40 pounds, so it would feel like you were only lifting the rest of the weight, which is 10 pounds.)

200

Complete this sentence: Using a lever lets you lift a heavy weight with little effort, but you must push over a ______ distance compared to how far the load actually moves.

longer

200

What scientific measurement is most famously attributed to Eratosthenes?

The circumference of the Earth.

300

Between Aristotle and Aristarchus, which thinker had a more accurate understanding of the structure of the universe?

Aristarchus

300

Is the moon’s path around the earth perfectly circular?

no

300

In the case of a lever, what term is used for its stationary part?

fulcrum

300

True or false: The moon reaches its greatest distance from Earth at apogee.

True

300

Why does the moon appear to change size so dramatically at different times?

It is an illusion that results from the way your brain tries to judge the size of what it sees.