Part A Unit 2 Exam

A planet that is ________ from the sun will take _________ to complete an orbit.

• The same size ; the same time
• Closer ; longer
• Farther ; longer
• Farther : less time

Which of the following is an approximate age of when the Sun and Earth formed, along with the rest of the solar system?

• 4.6 billion years ago
• 4.6 million years ago
• 13.7 billion years ago
• 1 million years ago

Earth eventually separated into its core and these two additional layers.

What are the two reference points that help in drawing the ellipse

• Foci
• polka dots
• ellipticals
• reference points

Select all answers that apply: What are 3 methods scientists use to determine how/when Earth was formed?

• Layers of Rocks (Law of Superposition)
• Radiometric Dating (radioactive decay, half-life, Carbon dating)
• Varve Count - Looking at the banding in rocks
• Kepler's Laws of Planetary Motion

1.5 billion years ago, the chemical composition of the atmosphere is ______________ to what it is today.

• similar
• heavier
• different
• lighter

Scientists believe this is one possible reason why the 1st atmosphere was lost.

• core
• solar nebula
• nuclear fusion
• solar wind

According to Kepler’s 1st Law, the shape of a planetary orbit is called ___________.

• a circle
• an ellipse
• an epicycle
• a gravitational constant

On which side of this orbit is the moon travelling at the highest velocity (speed)?

• Left
• Right
• Top
• Bottom

Read each clue and identify the correct law the clue is referring to: Each planet revolves around the sun with equal area in equal time.

• Kepler's 1st Law
• Kepler's 2nd Law
• Kepler's 3rd Law
• Law of Universal Gravitation