Warmup #2 science history of astronomers

Copernicus explained that

• the sun is at the center of the system of planets.

• the sun and the planets revolve around Earth

• there are only six planets.

• the geocentric system is correct.

Which astronomer discovered the factors that keep the planets in orbit?

• Kepler

• Galileo

• Newton

• Copernicus

The two factors that combine to keep the planets in orbit are

• orbital speed and mass.

• gravity and inertia.

• mass and inertia.

• gravity and orbital speed.

If there were no force of gravity, inertia would make the planets move

• forward.

• at a diagonal.

• in an ellipse.

• in a circle.

If there was no inertia, the planets would

• move in their orbit.

• revolve faster.

• be pulled into the sun.

• move straight.

The founder of modern astronomy is

• Newton

• Galileo

• Copernicus

Tycho Brahe predicted

• the sun-centered system.

• planetary motion.

• the four moons orbiting Jupiter.

• inertia and gravity.

The orbit of each planet is

• an eclipse.

• an ellipse.

• straight.

• round.

________ discovered that planets move in a specific shaped orbit.

• Kepler

• Newton

• Galileo

• Copernicus

Which astronomer(s) believed that Earth was at the center of the universe?

• Ptolemy

• Copernicus

• Galileo

• Aristotle