Astronomy Practice Questions - Chapter 3

What did Tycho Brahe contribute to our understanding of planetary motion?

• He discovered Kepler's three laws of planetary motion

• He developed a better model than Ptolemy's for the positions of the planets

• He made precise observations of the positions of the planets

• He proved that the Earth is the center of the universe

What did Johannes Kepler discover about the shape of planetary orbits?

• They are perfect circles

• They are ellipses with the Sun at one focus

• They are parabolas with the Sun at the vertex

• They are hyperbolas with the Sun at the center

What is the significance of the foci in an ellipse? (select ALL that apply)

• They determine the eccentricity of the ellipse

• They determine the shape of the ellipse

• They determine the size of the ellipse

• They determine the orientation of the ellipse

According to Kepler's Second Law, how much time should it take for this planet to pass through the long, thin area on the right?

• The same amount of time it took the same planet to pass through the short, wide area on the left.

• It should take about 3 weeks.

• It should take longer to pass through the long thin wedge on the right than it did for the short, wide wedge on the left.

Tags

NGSS.HS-ESS1-4

What does Kepler's third law describe?

• The shape of a planet's orbit is related to its eccentricity

• The size of a planet's orbit is related to its semimajor axis

• The speed of a planet's orbit is related to its distance from the Sun

• The period of a planet's orbit is related to its semimajor axis

According to Kepler's Second Law, where in this orbit would you expect the planet to be going at its greatest speed?

• A

• B

• Neither A nor B - this is a trick question

Tags

NGSS.MS-ESS1-2

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Kepler's 3rd law says P2 = a3

Remember that P is the orbital period of a planet (in years)

and
a is the distance of that planet from the sun (in AUs - Astronomical Units)

 

With that in mind, imagine a new planet has just been discovered that is 3.48 AUs from the Sun.  The new Wikipedia page for this planet states that it orbits the sun in 209 years.  You can see in the chart how this new planet measures up to the other existing ones. 

​Using what you know about Kepler's 3rd Law, would you say that the Wikipedia entry accurate, or does it need to be edited?

• Keep it! It's accurate!

• It's wrong! The orbital period should be larger.

• It's wrong! The orbital period should be smaller.

Tags

NGSS.MS-ESS1-2

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NGSS.MS-PS2-4

What does Kepler's third law allow us to calculate? (select ALL that apply)

• The amount of time it takes for that planet to orbit the Sun.

• The speed of a planet's motion at any point in its orbit.

• The average distances of planets from the Sun.

• The eccentricity of a planet's orbit.

Tags

NGSS.MS-ESS1-2

NGSS.MS-ESS1-3

NGSS.MS-PS2-4

What were the three laws proposed by Isaac Newton that govern the motions of all objects?

• Newton's laws of motion

• Kepler's laws of planetary motion

• Galileo's laws of motion

• Brahe's laws of planetary motion

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

What is the definition of momentum?

• The speed of an object

• The direction of an object's motion

• The amount of matter in an object

• The mass of an object multiplied by its velocity