Lesson 14A: Grasping Gravity

Lesson 14A: Grasping Gravity

Estimated Time: One forty-five minute class period

Indicators(s): Core Learning Goal 1

1.6.4 The student will manipulate quantities and/or numerical values in algebraic equations.

Indicators(s): Core Learning Goal 2

2.2.2. The student will explain the role of natural forces in the universe.

At least-- retention of an atmosphere, an agent of erosion and deposition, tides and deep ocean currents

Student Outcome(s):

The student will be able to establish ratios of comparison of weight on Earth to weight on other bodies by using Newton’s Law of Universal Gravitation.

Brief Description:

This is a NASA Ambassador lesson. (see outcome)

Background knowledge / teacher notes:

Students will need access to the website to view the technical reading and graphics.

Gravity is the attraction between all masses dependent on distance and the object’s mass. All objects produce some amount of gravity. The more mass an object has the more gravity it produces. There is no official measure for gravity in this sense of the word. You can, however, speak in relative terms: "Earth’s gravity is about six times that of the moon." Because the moon has less mass than the Earth, it also has less gravity.

One can compare properties such as these for the different planets, etc.. and hypothesize how the solar system formed, look for patterns in its structure, and contrast conditions on other planets and asteroids to those on Earth.

Mass is a measure of how much material is in an object, but weight is a measure of the attraction force exerted on that material to another mass; thus, mass and weight are proportional to each other.

Credit: Grasping Gravity. Background. Available: http://edmall.gsfc.nasa.gov/inv99Project.Site/Pages/gravity.abstract.html

Lisa Bruck

Lesson Description:

ENGAGE
Vocabulary: gravity, mass, weight.

Have students review their knowledge of gravity by listing what they already know.
Accommodation: Round Robin is a cooperative learning structure for accessing prior knowledge.

Students will then read the background information on gravity available:

http://edmall.gsfc.nasa.gov/inv99Project.Site/Pages/gravity.html#Background

Education Elements:

BACKGROUND INFORMATION

This site provides information about trajectories, orbits, and escape velocities and has a table that lists the escape velocities for the planets.

http://www.hq.nasa.gov/office/pao/History/conghand/traject.htm

EXPLORE

Students should proceed to the online exploration:

Grasping Gravity. Procedure. Available:

http://edmall.gsfc.nasa.gov/inv99Project.Site/Pages/gravity.html#Procedure

Accommodation: If this investigation were printed for students they can use highlighters to note vocabulary definitions and/ or the outcome for the investigation.

Education Elements:

BACKGROUND

This site is part of the on-line astronomy course "From Stargazers to Starships". It provides the learner with information and historical perspectives about our understanding of gravity and related solar system topics.

http://www-spof.gsfc.nasa.gov/Lstargcc/Sconct12.htm

EXPLAIN

Journal Write:

Complete the Assessment/ Reflection. Omit Question 5

Which body had the smallest gravity ratio number? Why do you believe it was so small?

Which body had the largest gravity ratio? Why do you believe it was so large?

Which asteroid has the smallest gravity ratio number? What does this tell us about the difference between the two asteroids?

How did your original hypothesis compare to your results concerning gravity?

EXTEND

Can you make any correlation between gravity and composition and density of a planet or asteroid?

Go back to your planet information buttons on the planets and asteroids. Could gravity have any affect on the composition and density of the body? Explain your answer.

Education Elements:

BACKGROUND

This JPL site is the fourth chapter in an on line tutorial that describes the Basics of Space Flight. It includes information on gravity assist trajectories.

http://www-a.jpl.nasa.gov/basics/bsf4-1.html

EVALUATE

Journal Write: Explain how the Law of Universal Gravitation allows you to compare your weight on Earth to weight on other celestial bodies in the solar system.

Materials:

Computer access and Internet access

Calculator

Pen/pencil

Resources:

Credit: Goddard Space Flight Center Earth and Space Sciences Education Project (GESSEP)

Principal Investigator: Steve Gilligan. Co-Investigator: Vern Smith

Grasping Gravity. Background. Available: http://edmall.gsfc.nasa.gov/inv99Project.Site/Pages/gravity.abstract.html

Lisa Bruck

ENGAGE	Vocabulary: gravity, mass, weight. Have students review their knowledge of gravity by listing what they already know. Accommodation: Round Robin is a cooperative learning structure for accessing prior knowledge. Students will then read the background information on gravity available: http://edmall.gsfc.nasa.gov/inv99Project.Site/Pages/gravity.html#Background Education Elements: BACKGROUND INFORMATION This site provides information about trajectories, orbits, and escape velocities and has a table that lists the escape velocities for the planets. http://www.hq.nasa.gov/office/pao/History/conghand/traject.htm
EXPLORE	Students should proceed to the online exploration: Grasping Gravity. Procedure. Available: http://edmall.gsfc.nasa.gov/inv99Project.Site/Pages/gravity.html#Procedure Accommodation: If this investigation were printed for students they can use highlighters to note vocabulary definitions and/ or the outcome for the investigation. Education Elements: BACKGROUND This site is part of the on-line astronomy course "From Stargazers to Starships". It provides the learner with information and historical perspectives about our understanding of gravity and related solar system topics. http://www-spof.gsfc.nasa.gov/Lstargcc/Sconct12.htm
EXPLAIN	Journal Write: Complete the Assessment/ Reflection. Omit Question 5 Which body had the smallest gravity ratio number? Why do you believe it was so small? Which body had the largest gravity ratio? Why do you believe it was so large? Which asteroid has the smallest gravity ratio number? What does this tell us about the difference between the two asteroids? How did your original hypothesis compare to your results concerning gravity?
EXTEND	Can you make any correlation between gravity and composition and density of a planet or asteroid? Go back to your planet information buttons on the planets and asteroids. Could gravity have any affect on the composition and density of the body? Explain your answer. Education Elements: BACKGROUND This JPL site is the fourth chapter in an on line tutorial that describes the Basics of Space Flight. It includes information on gravity assist trajectories. http://www-a.jpl.nasa.gov/basics/bsf4-1.html
EVALUATE	Journal Write: Explain how the Law of Universal Gravitation allows you to compare your weight on Earth to weight on other celestial bodies in the solar system.