Name Gravity and the Solar System - mrscienceut.netmrscienceut.net/2012GravityWkbk.pdf · Name...

Name _____________________________________________________________

Gravity and the Solar System

At the end of this workbook, students should understand the following concepts:

Standard/State Core

Description (State Core)

SciBer Text Understand and correctly use unit vocabulary. III.3.b Inform how the mass of an object affects its

gravity. III.3.c Indicate how gravity keeps the Solar System

together.

1

Bill Nye – Gravity Worksheet 1. ____________________________ is the force that makes the Earth go around the Sun, the Earth and other planets round like a ball, and everything fall. 2. Everything, every piece of matter in the universe, has gravity. a. True b. False 3. The Earth’s gravity does not pull the oceans and the atmosphere towards the center of the Earth. a. True b. False 4. Since the bowling ball is heavier, it will land FIRST. a. True b. False 5. The pull of gravity affects everything. a. True b. False 6. The pull of gravity does not extend over great distances. a. True b. False 7. The pull of gravity is so strong that it can keep the Earth in orbit around it even though it’s 150,000,000 kilometers away. a. True b. False 8. Gravity keeps all the planets in their orbits. a. True b. False 9. Weight comes from our mass, the Earth’s mass, and gravity. a. True b. False

2

10. If it wasn’t for gravity, everyone could juggle! a. True b. False 11. The larger something is, the greater its gravitational pull. a. True b. False 12. What has gravity? ____________________________________________________ 13. Gravity does not work on everything. a. True b. False 14. You would weigh the same on any planet in the Solar System. a. True b. False 15. Planets end up as balls because of gravity. a. True b. False 16. When you ride your bike, you are not fighting gravity. a. True b. False 17. Gravity does not pack things together. a. True b. False 18. Gravity does not make all the planets round. a. True b. False

3

More or Less (activity from Janice Van Cleave’s Solar System)

Materials

Calculator

Procedure

1. Complete the table you have been given by calculating each planet’s mass ratio, which is the ratio of a planet’s mass to the mass of Earth. NOTE: The mass of planets is measured in trillion trillion kilograms (kg). For example, the mass ratio of Mercury is:

mass ratio = planet’s mass ÷ Earth’s mass = .33 ÷ 5.9 = .06/1

(Round to one decimal point.) Mercury’s mass ratio is .06/1, which means that Mercury’s mass is .06 (6%) that of Earth. Hint: divide the amount in the mass column by 5.9

Mass Ratios of the Planets to Earth Planet Mass (trillion trillion kg) Mass Ratio (planet/Earth)

Mercury .33 .06/1 Venus 4.87 /1 Earth 5.9 /1 Mars .64 /1

Jupiter 1,899 /1 Saturn 569 /1 Uranus 86.9 /1

Neptune 103 /1

4

Chaos Among the Planets Kate Ramsayer From Science News for Kids June 1, 2005. Once upon a time, many, many years ago, the giant planets in our Solar System took different paths around the Sun than they follow now. Jupiter, Saturn, Uranus, and Neptune were once bunched together and closer to the Sun, says an international team of scientists. Under the influence of gravity, the planets broke out of their original orbits and began violently rearranging the outer Solar System.

A new theory suggests that the four giant planets, shown here in their current orbits around the Sun, were once much closer together. Nature

It's "a fairy tale of the early Solar System," says Hal Levison. He's a planetary scientist with the Southwest Research Institute in Boulder, Colo., and was one of the researchers who developed a computer simulation of the planets' movements. As the scientists tell it, the tale starts a few million years after the Solar System's birth. At first, the four giant planets had compact orbits. Neptune, for example, was only half as far away from the Sun as it now. A slowly circulating band of ice, dust, and gas lay beyond these planets. Ice, dust, and gas might not seem like much of a match for huge planets. But the researchers say that the pull of gravity between the particles and the planets caused the planets to gradually break out of their tight-knit group. Jupiter moved a bit closer to the Sun, and the other three planets moved further away.

5

All was peaceful in the solar kingdom until the orbits of Saturn and Jupiter aligned so that Saturn took exactly twice as long as its neighbor to go around the Sun. The increased gravitational tug of the two planets acting together caused an avalanche of effects. Saturn's orbit changed shape slightly, which threw off the orbits of Uranus and Neptune. The orbits of these two planets started looking like squished ovals. At times, the two planets even crossed paths. And that's when things got really crazy. Uranus and Neptune started hurtling through the band of ice, dust, and gas, scattering the debris throughout the Solar System. The planets themselves ended up in their current orbits. In the meantime, some of the scattered material became trapped around Jupiter, the scientists suggest. This could account for the presence of objects, known as the Trojan asteroids, that both lead and trail the planet. Some of the debris could have been flung closer to our home, slamming into the Moon and the Solar System's inner planets. This bombardment may have created the huge craters on the Moon and elsewhere. No one knows for sure whether all this really happened. But, by using computers to play complex games of "what if," scientists can get a better sense of what might have happened to create the Solar System as we know it.

Questions 1. According to the article, these four planets were bunched together and nearer to the Sun. a. ___________________________________________________________ b. ___________________________________________________________ c. ___________________________________________________________ d. ___________________________________________________________ 2. This force caused the violent rearrangement of our Solar System. _______________________________________________________

6

3. __________________ moved a bit closer to the Sun changed shape slightly, and the other three planets moved __________________ away. 4. This is the group of asteroids that both lead and trail Jupiter. __________________________________________________________________ 5. Debris flung towards the inner planets may have created the huge _____________ on the Moon and elsewhere. 6. Scientists are positive this really happened. True False

Gravity Exploration Part A: How much would you weigh on other worlds? The more mass an object has, the more gravity it has. Objects which have more mass than Earth would have more gravity than Earth. A person would weigh more on these worlds than they do on Earth. Using the weight for a person on Earth, calculate that person’s weight on other worlds.

7

Location Person’s Weight on Earth (lbs)

Gravity Calculated Weight (round decimals to a whole number)

Sun 120 27 Mercury 120 .38

Venus 120 .86 Moon 120 .17 Mars 120 .38 Ceres 120 .03

Jupiter 120 2.87 Jupiter’s Moon Io

120 .18

Jupiter’s Moon Europa

120 .13

Jupiter’s Moon

Ganymede

120 .15

Jupiter’s Moon Callisto

120 .13

Saturn 120 1.32 Uranus 120 .93

Neptune 120 1.23 Pluto 120 .067

1. On which member of the Solar System (excluding the Sun) would you weigh… a. most - ____________________________________________________

X

X

X

X

X

X

X

X

X

X

X

X

X

X

X

8

b. least - ____________________________________________________ 2. Why do you think you would weigh less on Mercury than on Neptune? __________________________________________________________________ __________________________________________________________________ Part B: How far could you jump on other planets and the Moon? A person stands on the floor and jumps as far as they can five times. The length of each jump was recorded in the table below. Using that information, calculate the average distance. Take that number and write it in the “Average Length” column.

Jump 1 Jump 2 Jump 3 Jump 4 Jump 5 Average

52” 49” 53” 50” 51” “

(To find the average, add Jump 1 + Jump 2 + Jump 3 + Jump 4 + Jump 5 and then divide your total by 5. This is the distance that goes

in the average column.)

Location Average Length

Gravity Length (round

decimals to a whole number)

Convert to Feet (Divide Length by

12)

Sun in. 27 in. XXXXXXXXXX Mercury in. .38 in. ft.

Venus in. .86 in. ft. Moon in. .17 in. ft.

÷

÷

÷

÷

9





12)

Mars in. .38 in. ft. Ceres in. .03 in. ft.

Jupiter in. 2.87 in. ft. Jupiter’s Moon

Io in. .18 in. ft.


in. .13 in. ft.

Jupiter’s Moon Ganymede

in. .15 in. ft.


in. .13 in. ft.

Saturn in. 1.32 in. ft. Uranus in. .93 in. ft.

Neptune in. 1.23 in. ft. Pluto in. .067 in. ft.

1. On which member of the Solar System (excluding the Sun) would you be able to jump the: a. farthest - ___________________________________________________ b. shortest - ___________________________________________________

÷

÷

÷

÷

÷

÷

÷

÷

÷

÷

÷

10

2. Why do you think you would be able to jump farther on Mercury than on Neptune? __________________________________________________________________ __________________________________________________________________ 3. If you wanted to break the world record in standing broad jump, on which planet would you choose to perform your jump? Why? __________________________________________________________________ __________________________________________________________________ 4. What other sporting records might you be able to break on this planet? __________________________________________________________________ __________________________________________________________________ Part C: How high can you jump on other planets? The larger the mass of the planet, moon or star, the more it would pull on you and the harder it would be to jump. A person stands on the floor and jumps as high as they can three times. The height of each jump was recorded in the table below. Using that information, calculate the average height. Take that number and write it in the “Average Height” column.

Jump 1 Jump 2 Jump 3 Average

27” 22” 30” ” (To find the average, add Jump 1 + Jump 2 + Jump 3 and then divide your total by 5. This is the distance that goes in the average column.)

11





12)

Sun in. 27 in. XXXXXXXXXX Mercury in. .38 in. ft.

Venus in. .86 in. ft. Moon in. .17 in. ft. Mars in. .38 in. ft. Ceres in. .03 in. ft.

Jupiter in. 2.87 in. ft. Jupiter’s Moon

Io in. .18 in. ft.


in. .13 in. ft.

Jupiter’s Moon Ganymede

in. .15 in. ft.


in. .13 in. ft.

Saturn in. 1.32 in. ft. Uranus in. .93 in. ft.

Neptune in. 1.23 in. ft. Pluto in. .067 in. ft.

÷

÷

÷

÷

÷

÷

÷

÷

÷

÷

÷

÷

÷

÷

÷

12

1. On which member of the Solar System would you be able to jump the: a. highest - ____________________________________________________ b. lowest - ____________________________________________________ 2. Why do you think you would be able to jump higher on Mercury than on Neptune? __________________________________________________________________ __________________________________________________________________ 3. If you wanted to break the world record in high jump, on which planet would you choose to perform your jump? Why? __________________________________________________________________ __________________________________________________________________ 4. What other sporting records might you be able to break on this planet? __________________________________________________________________ __________________________________________________________________

We have your rovers. If you want them back, send 20 billion in Martian money. No funny business or you will never see them again.

- Seen on a hall wall at NASA's Jet Propulsion Labs

13

Student Reader Around the World

A microgravity environment is created by letting things fall freely. NASA uses airplanes, drop towers, and small rockets to create a microgravity environment lasting a few seconds to several minutes. Eventually, freefall has to come to an end because Earth gets in the way. When scientists want to conduct experiments lasting days, weeks, months, or even years, it is necessary to travel into space and orbit Earth. Having more time available for experiments means that slower processes and more subtle effects can be investigated. To see how it is possible to establish microgravity conditions for long periods of time, it is first necessary to understand what keeps a spacecraft in orbit. Ask just about anybody what keeps satellites and Space Shuttles in orbit and you will probably hear, "There is no gravity in space." This is simply not true. Gravity is what keeps a satellite or Space Shuttle from drifting into space. It does this by bending an orbiting object's path into a circular shape. To explain how this works, we can use an example presented by English scientist Sir Isaac Newton. In a book he wrote in 1673, Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy), Newton explained how a satellite could orbit Earth. Newton envisioned a very tall mountain on Earth whose peak extended above Earth's atmosphere. This was to eliminate friction with Earth's atmosphere. Newton then imagined a cannon at the top of that mountain firing cannonballs parallel to the ground. As each cannonball was fired, it was acted upon by two forces. One force, due to the explosion of the black powder, propelled the cannonball straight outward. If no other force were to act on the cannonball, the shot would travel in a straight line and at a constant velocity. But Newton knew that a second force would also act on the cannonball: Earth's gravity would cause the path of the cannonball to bend into an arc ending at Earth's surface.

14

Newton demonstrated how additional cannonballs would travel farther from the mountain if the cannon were loaded with more black powder each time it was fired. With each shot, the path would lengthen and soon the cannonballs would disappear over the horizon. Eventually, if a cannonball were fired with enough energy it would fall entirely around Earth and come back to its starting point. This would be one complete orbit of Earth. Provided no force other than gravity interfered with the cannonball's motion, it would continue circling Earth in that orbit. In essence, this is how the Space Shuttle stays in orbit. The Shuttle is launched on a path that arcs above Earth so that the Orbiter is traveling parallel to the ground at the right speed. For example, if the Shuttle climbs to a 160-kilometer-high orbit, it must travel at a speed of about 28,300 kilometers per hour to achieve an orbit. At that speed and altitude, the Shuttle's falling path will be parallel to the curvature of Earth. Because the Space Shuttle is freefalling around Earth, a microgravity environment is created that will last as long as the Shuttle remains in orbit.

15

Around the World (a NASA Quest activity)

Materials World globe Small ball 2 meters of string

Safety Concerns: Swing ball. Activity must be done in an open area away from other students.

Procedure 1. Set up your equipment as shown in the picture. 2. One team member stands above the large ball and holds the end of the string. The second team member’s job is to move the small ball in different ways to answer questions. 3. Write down your answers (complete and full sentences) where indicated and draw pictures to show what happened. Draw the pictures looking straight down on the two balls.

16

1. What path does the satellite (small ball) follow when it is launched straight out from Earth? (Include both written and drawn explanations.) ___________________________________________ ___________________________________________ ___________________________________________ ___________________________________________ ___________________________________________ 2. What path does the satellite follow when it is launched at different angles from Earth’s surface? ___________________________________________ ___________________________________________ ___________________________________________ ___________________________________________ 3. What effect is there from launching the satellite and different speeds? __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

17

4. What must you do to launch the satellite so it completely orbits Earth? __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 5. Using the results of your investigation and the information contained in the student reader, write a paragraph that explains how satellites remain in orbit. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 6. Explain how this activity demonstrates how the planets remain in orbit around the Sun. (Note: a sentence or two is not an acceptable answer. Take time to think about your answer and make sure it answers the question.) __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

18

Moons, Rings, and Relationships Materials Rubber ball Paper, markers, pencils

Procedure Part I: What Do We Know about Objects in Orbit? 1. Predict what you think will happen to a ball after it rolls off the edge of a table — first when it’s rolling slowly, then when it’s rolling quickly. Record your answers below. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 2. To test your prediction, your assignment is to develop an experiment that tests your prediction. You will be using a rubber ball for your experiment. Attach a copy of your experiment to this paper. Make sure you explain why your ball follows the path it does. 3. Look a Figure 1. Imagine an enlarged mountain on Earth with a baseball player on top who hits a pitched ball from space. The mountain is very high and that most of the atmosphere is below the top of the mountain. What happens when the baseball player hits the ball? Why does ball follow the path it does? Why doesn’t the hit baseball fly off into space? What would happen if the player hits the baseball harder? Record your answers. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

Saturn Educator Guide • Cassini Program website — http://www.jpl.nasa.gov/cassini/educatorguide • EG-1999-12-008-JPL

L E S S O N

3

75

Figure 1

Baseball Player Hitting a Baseball Pitched from Space

19

4. Look at Figure 2. Predict what would happen if a cannonball were to be blown out of the cannon with more and more force? Record your answer. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 5. What keeps Earth’s Moon in orbit? Record your answer. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ Part IIa: Making Connections to Saturn — the Nature of the Rings 1. What orbits Saturn? What do you know about the orbits of these objects? Record your answers. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 2. Look at Figure 3 (an illustration a close-up view of Saturn’s rings, a ring particle, and a house). Develop explanations about the illustration. How do you think the individual particles of Saturn’s rings move? Record your answers. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________


L E S S O N

3

77

Figure 2

Cannon Shooting a Cannonball


L E S S O N

3

79

Figure 3W

m. K

. Har

tman

n

20

Part IIb: Making Connections to Saturn — Orbital Speed 1. How is the speed the rings and moons move around Saturn different? Does it depend on the mass of the orbiting object? Does it depend on the distance of the orbiting body (moon or ring particle) from the Saturn? Record your answers. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 2. You will test your ideas (hypotheses) about orbital speed will be tested by graphing the orbital speeds of some of Saturn’s moons and also ring particles at the inner and outer edges of the A ring. Using Figures 4 & 6, complete the graph comparing orbital speed vs. distance from center of Saturn. 3. Once complete, explain how orbital speed changes as you go farther from the center of Saturn. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ Part III: Assessment 1. Write a description of the forces that keep the planets and asteroids of our Solar System in orbit about the Sun. __________________________________________________________________ __________________________________________________________________


L E S S O N

3

81

Distance from Center Speed of MoonMoon or Ring Special Features or Behavior of Saturn (103 km) in Orbit (km/sec)

A Ring — Forms outer edge of Cassini Division 122.2 17.63Inner Edge

Pan Orbits in Encke Gap, sweeping it clean 133.6 16.84

A Ring – “Guarded” in its outer edge by the moon Atlas 136.8 16.66Outer Edge

Atlas May keep the outer edge of the A ring 137.6 16.63well defined

Pandora Shepherd moon; helps keep the F ring narrow 141.7 16.38

Epimetheus Irregular; may have been joined with Janus 151.4 15.87

Mimas Has giant crater called Herschel; looks like 185.5 14.32“Death Star” moon

Enceladus Icy, shiny; may have ice geysers that feed E ring 238.0 12.63

Tethys Has large trench called Ithaca Chasma; large 294.7 11.34crater called Odysseus

Telesto Same orbit as Tethys (60º behind); less massive 294.7 11.34than Tethys

Dione Cratered leading face; wispy features on 377.4 10.03trailing hemisphere

Rhea Largest icy satellite; densely cratered 527.0 8.49

Use this information to complete your plot of Orbital Speed vs. Distance from Center of Saturn.

Figure 4

Moon and A Ring Data — for Students


L E S S O N

3

85

Figure 6

Use this information to complete your plot of Orbital Speed vs. Distance from Center of Saturn.

Moon and A Ring Data — for the Teacher(shading shows items for students to plot)

Distance from Center Speed of MoonMoon or Ring Special Features or Behavior of Saturn (103 km ) in Orbit (km/sec)

A Ring — Forms outer edge of Cassini Division 122.2 17.63 Inner Edge

Pan Orbits in Encke Gap, sweeping it clean 133.6 16.84

A Ring – “Guarded” in its outer edge by the moon Atlas 136.8 16.66 Outer Edge

Atlas May keep the outer edge of the A ring 137.6 16.63well defined

Prometheus Shepherd moon; helps keep the F ring narrow 139.4 16.53

Pandora Shepherd moon; helps keep the F ring narrow 141.7 16.38

Epimetheus Irregular; may have been joined with Janus 151.4 15.87

Janus Irregular; trades orbits with 151.5 15.85Epimetheus

Mimas Has giant crater called Herschel; looks like 185.5 14.32“Death Star” moon

Enceladus Icy, shiny; may have ice geysers that feed E ring 238.0 12.63

Tethys Has large trench called Ithaca Chasma; large 294.7 11.34crater called Odysseus

Telesto Same orbit as Tethys (60º behind); less massive 294.7 11.34than Tethys

Calypso Same orbit as Tethys (60º ahead); 294.7 11.34less massive than Tethys

Dione Cratered leading face; wispy features on 377.4 10.03trailing hemisphere

Helene Same orbit as Dione (60º ahead); 377.4 10.03less massive than Dione

Rhea Largest icy satellite; densely cratered 527.0 8.49


L E S S O N

3

83

Figure 5

ORBITAL VELOCITY (km/sec)

18

DIS

TAN

CE

FRO

M C

ENTE

R O

F SA

TURN

(103

km)

100

17 16 15 14 13 12 11 10 9 820

030

040

060

050

0

Orbital Speed vs. Distance from Center of Saturn —for Students to Complete

Orb

ital

Spee

d v

s. D

ista

nce

fro

m C

ente

r of

Sat

urn

21

__________________________________________________________________ __________________________________________________________________ 2. Write down your predictions how the orbital speed of the planets in our Solar System changes with distance from the center of the Sun. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 3. Interpret the graph (Orbital Speed vs. Distance from Sun) and write a summary of your discoveries about orbital speed. (How does orbital speed depend on distance from the center of Saturn? For a given distance from the center of Saturn, does the orbital speed depend on mass or size? ) __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 4. Compare your group’s conclusions with your initial predictions, writing down how your ideas changed. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________


L E S S O N

3

89

Figure 8

Use this chart to plot Orbital Speed vs. Distance from Sun.

Venus 108.2 35.0 4.87 12,104

Earth 149.6 29.8 5.97 12,756

Mars 227.9 24.1 0.642 6,794

Asteroid Ceres 414 17.9 Unknown 1,000

Jupiter 778.3 13.1 1,900 142,984

Solar System Data — for Students

Object Distance from Orbital Speed Mass DiameterSun (× 106 km) (km/sec) (× 1024 kg) (km)


L E S S O N

3

91

Figure 9

ORBITAL VELOCITY (km/sec)

40

DIS

TAN

CE

FRO

M T

HE

SUN

(106

km)

0

30 20 10 010

020

050

080

070

030

040

060

0

Orbital Speed vs. Distance from Sun — for Students to Complete

Orb

ital

Spee

d v

s. D

ista

nce

fro

m S

un

22

Free Falling (an activity from the Texas Space Grant Consortium) Four hundred years ago--or so the story goes--Galileo Galilei started dropping things off the Leaning Tower of Pisa: Cannon balls, musket balls, gold, silver and wood. He might have expected the heavier objects to fall faster. Not so. They all hit the ground at the same time, and so he made a big discovery: gravity accelerates all objects at the same rate, regardless of their mass or composition. Was Galileo correct? Materials

Triple-Beam Balance Four Kodak Film Canisters Washers Marker

Safety Concerns: None. Procedure 1. Label the film canisters 1-4. Place one washer in canister one, two in canister two, three in canister three and four in canister four. 2. Using the triple-beam balance, determine the mass of each canister. Record it on your table. 3. Select two canisters and hold them at arm’s length, facing the same way. 4. Release both canisters and observe if they both hit the ground at the same or different time. Repeat the process three times. 5. Repeat for every combination of canisters.

23

Free Falling Data Table (an activity from the Texas Space Grant Consortium)

Mass of Canisters Canister # Mass (grams)

1 2 3 4

Observations __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 1. Are your results the same for each trial? Explain. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ _________________________________________________________________

24

2. Does your observation verify Galileo’s hypothesis? Explain. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ _________________________________________________________________

3. Would an elephant fall faster than a mouse? Explain. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ _________________________________________________________________

We cannot teach people anything; we can only help them discover it within themselves.

-Galileo Galilei

Name Gravity and the Solar System - mrscienceut.netmrscienceut.net/2012GravityWkbk.pdf · Name...

Documents

Transcript of Name Gravity and the Solar System - mrscienceut.netmrscienceut.net/2012GravityWkbk.pdf · Name...