Exit Check 3.1 - Kepler's Laws

3.1.1

Planets orbit the Sun in a shape called a(n)

• circle

• ellipse

• focus

• perihelion

Answer explanation

This question links to success criteria 3.1.1: I can use Kepler’s 1st Law to describe the orbit shape of any body around another.

If you got it correct place a check mark in the question results section. If you got it incorrect place an X in that section. If this was a redemption question, cross out the one X and replace it with a check mark.

Tags

NGSS.HS-ESS1-4

3.1.1

The path a planet travels around the sun is called its 

• orbit

• ellipse

• barycenter

• precession

Answer explanation

Kepler’s First Law tells us that all orbits are shaped like ellipses, not perfect circles. To describe how stretched or round the orbit is, we use the term eccentricity. An orbit with low eccentricity is almost a circle. An orbit with high eccentricity is more stretched out. Use this understanding to compare the shapes of different orbits.

Tags

NGSS.HS-ESS1-4

3.1.1

What has an eccentricity of zero

• a straight line

• a large ellipse

• a circle

• a small ellipse

Answer explanation

Kepler’s First Law tells us that all orbits are shaped like ellipses, not perfect circles. To describe how stretched or round the orbit is, we use the term eccentricity. An orbit with low eccentricity is almost a circle. An orbit with high eccentricity is more stretched out. Use this understanding to compare the shapes of different orbits.

3.1.1

What does Kepler's 1st Law state?

• all planets move in elliptical shaped orbits around the sun

• all ellipses have one foci

• the area that a planet revolves around the sun is equal

• the speed that a planet revolves around the sun changes

Answer explanation

Kepler’s First Law tells us that all orbits are shaped like ellipses, not perfect circles. To describe how stretched or round the orbit is, we use the term eccentricity. An orbit with low eccentricity is almost a circle. An orbit with high eccentricity is more stretched out. Use this understanding to compare the shapes of different orbits.

Tags

NGSS.HS-ESS1-4

3.1.2

Where is the planet moving faster

• Position A to B

• Position B to C

• Position H to I

• Position I to J

Answer explanation

Kepler’s Second Law tells us that an object in orbit moves faster when it is closer to the object it’s orbiting and slower when it is farther away. It also tells us that the area swept out in a certain amount of time will always be the same, even if the shape of that area looks different. Use both of these ideas to decide where the object is moving fastest or slowest in its orbit.

Tags

NGSS.HS-ESS1-4

3.1.2

Where is the planet moving slowest

• Position A to B

• Position B to C

• Position H to I

• Position I to J

Answer explanation

This question links to success criteria 3.1.2: I can use Kepler’s 2nd Law to predict when an orbiting body travels faster or slower in its own orbit.

If you got it correct place a check mark in the question results section. If you got it incorrect place an X in that section. If this was a redemption question, cross out the one X and replace it with a check mark.

Tags

NGSS.HS-ESS1-4

3.1.3

What did Kepler discover about planets and their orbital speed?

• Planets closest to the Sun will orbit with the fastest orbital speed.

• Planets with the greatest mass will orbit the Sun with the fastest orbital speed.

• Planets furthest from the Sun will orbit with the fastest orbital speed.

• Planets with the least mass will orbit the Sun with the fastest orbital speed.

Tags

NGSS.HS-ESS1-4

3.1.2

According to Kepler's second law, in the picture which of the following is true for all of the purple sectors shown in the diagram

• They are all show areas where the object is accelerating while the white sections show areas of constant velocity.

• They all have the same area to show that they cover the same amount of displacement

• They all have the same area to show that they take the same amount of time

• They all go slow, as shown by the use of a darker color

Answer explanation

Kepler’s Second Law tells us that an object in orbit moves faster when it is closer to the object it’s orbiting and slower when it is farther away. It also tells us that the area swept out in a certain amount of time will always be the same, even if the shape of that area looks different. Use both of these ideas to decide where the object is moving fastest or slowest in its orbit.

Tags

NGSS.HS-ESS1-4

3.1.3

While working as an intern for an astrophysics research telescope, you identify three exoplanets in another solar system orbiting their star. Planet A has an the largest orbital radius, Planet B has the smallest orbital radius, and Planet C has a medium orbital radius.  What should you conclude about their orbital periods??

• Planet C takes the longest to complete one orbit. Planet B takes the least time to complete one orbit.

• Planet A takes the longest to complete one orbit. Planet C takes the least time to complete one orbit.

• Planet B takes the longest to complete one orbit. Planet C takes the least time to complete one orbit.

• Planet A takes the longest to complete one orbit. Planet B takes the least time to complete one orbit.

Tags

NGSS.HS-ESS1-4

3.1.3

If a moon’s orbital radius doubles, by what factor does its orbital period change?

• The period increases by a factor of 2.82

• The period decreases by a factor of 2.82

• The period increases by a factor of 5.20

• The period increases by a factor of 8.28

Tags

NGSS.HS-ESS1-4

NGSS.HS-PS2-4