Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Earth's rotation wikipedia , lookup
Kuiper belt wikipedia , lookup
Exploration of Io wikipedia , lookup
Planet Nine wikipedia , lookup
Scattered disc wikipedia , lookup
Exploration of Jupiter wikipedia , lookup
Planets beyond Neptune wikipedia , lookup
Dwarf planet wikipedia , lookup
Jumping-Jupiter scenario wikipedia , lookup
History of Solar System formation and evolution hypotheses wikipedia , lookup
Late Heavy Bombardment wikipedia , lookup
Name _____________________________________________________________ Gravity Workbook 1 This Workbook covers the following Utah State Core Standards: STANDARD III: Students will understand the relationship and attributes of objects in the Solar System. Objective 3: Describe the forces that keep objects in orbit in the Solar System. a. Describe the forces holding Earth in orbit around the Sun, and the Moon in orbit around Earth. b. Relate a celestial object’s mass to its gravitational force on other objects. c. Identify the role gravity plays in the structure of the Solar System. 2 Quicker (activity from Astronomy for Every Kid by Janice Van Cleave) Materials Long stick Short stick Modeling clay Procedure 1. Place a walnut-sized ball of clay on the end of the long stick and one on the end of the short stick. 2. Hold the long stick and short stick up and down, sideby-side, with the edge without the clay ball on the ground. 3. Release both at the same time. 1. Explain what happened when you dropped the sticks. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 3 2. From your notes, you know that planets nearer the Sun revolve faster than planets away from the Sun. Explain how activity demonstrates that concept. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ Staying Up While Falling Down Materials Plastic golf ball Straw Different size washers Safety Concerns: Moving plastic golf ball. Discuss safe procedures for twirling ball and pulling washers. Procedure 1. Thread the string through the straw. DO NOT tie a washer to the other end of the string. Your set up should look like the diagram below (except no washer). 4 2. Hold the straw and swing the ball in a circle so that it “orbits” the straw. (Be sure to keep moving your hand at a constant speed.) Record below what you see happen. __________________________________________________________________ __________________________________________________________________ 3. Tie a small washer to the end of the string. Hold the straw and swing the ball in a circle so that it “orbits” the straw. (Be sure to keep moving your hand at a constant speed.) Record below what you see happen. __________________________________________________________________ __________________________________________________________________ 4. Tie a medium sized washer to the end of the string. Hold the straw and swing the ball in a circle so that it “orbits” the straw. (Be sure to keep moving your hand at a constant speed.) Record below what you see happen. __________________________________________________________________ __________________________________________________________________ 5. Tie a large washer to the end of the string. Hold the straw and swing the ball in a circle so that it “orbits” the straw. (Be sure to keep moving your hand at a constant speed.) Record below what you see happen. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 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 5 6. Tie two or more large washers the end of the string. Hold the straw and swing the ball in a circle so that it “orbits” the straw. (Be sure to keep moving your hand at a constant speed.) Record below what you see happen. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 7. Explain how this experiment demonstrates planets revolving around the Sun. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ Orbital Period: Time of Revolution (an activity from Janice Van Cleave’s A+ Projects in Astronomy) Question How does distance effect the orbital period of an orbiting planet? Materials Metal washer 6-foot string Ruler Timer 6 Safety Concerns: Flying washer. Student must make sure washer is properly tied to string and space is left between students swinging the washer. Procedure 1. Tie a washer to the cord. 2. On the cord, measure 18” from the washer and time a knot in the cord. 3. Measure 18” from the knot and tie a second knot in the cord. Repeat this process a third time, making a third knot. 4. Hold the cord at the first knot (18”) from the washer and swing your arm so that the washer spins above your head. 5. Find the slowest speed that will keep the washer “in orbit.” 6. Have a partner count the revolutions. The partner will say “Start” and count the number of revolutions in 10 seconds. 7. Stop when your partner says, “stop.” 8. Calculate the orbital period, T (time per revolution) of the washer by dividing the time by the number of revolutions. For example, if your partner counted five revolutions in 10 seconds the orbital period would be: T = orbital period = time number of revolutions = 10 seconds ÷ 5 revolutions = 2 seconds per revolution (2 seconds/revolution) This is read as 2 seconds per revolution and means that it took 2 seconds for the washer to travel 1 revolution. 7 9. Repeat steps 6 thru 8 for a total of five trial measurements. 10. Repeat steps 6 thru 8 for the two other distances (36” at the second knot and 54” at the third knot.) 11. Record your data in the Orbital Period by Orbit Distance table. Make sure you figure the average of the five trials. For example: Trial 1 – 2 seconds/revolution; Trial 2 – 2.7 seconds/revolution; Trial 3 – 1.9 seconds/revolution; Trial 4 – 2.2 seconds/revolution; Trial 5 – 1.4 seconds/revolution. = 2 + 2.7 + 1.9 + 2.2 + 1.4 = 10.2 (total five trials) = 10.2 ÷ 5 (number of trials) = 2.04 seconds/revolution (average of the five trials) Question How does distance effect the orbital period of an orbiting planet? 1. Complete the table below. Orbital Period by Orbital Distance Orbital Distance (Inches) Trial 1 Trial 2 Trial 3 Trial 4 Trial 5 Average 18” 36” 54” 8 2. Using the data in your table and graph, explain how the length of the string effects the orbital period (revolutions/second) of an orbiting planet. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 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. 9 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. Data Table Mass of Canisters Canister # Mass (grams) 1 2 3 4 Observations __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ 10 1. Are your results the same for each trial? Explain. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ _________________________________________________________________ 2. Does your observation verify Galileo’s hypothesis? Explain. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ _________________________________________________________________ 3. Would an elephant fall faster than a mouse? Explain. __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ _________________________________________________________________ 11 Gravity Exploration Part A: How much would you weigh on other bodies? The more mass an object has, the more gravity it has. Objects that have more mass than Earth would have more gravity than Earth. A person would weigh more on these objects than they do on Earth. Write your weight in the “Weight on Earth” column. If you don’t know your weight, use 93 pounds. Figure out how much you would weigh on other bodies. Location Your Weight Gravity on Earth Calculated Weight (round decimals to a whole number) Sun X 27 Mercury X .38 Venus X .86 Moon X .17 Mars X .38 Ceres X .03 Jupiter X 2.87 X .18 X .13 X .15 X .13 X 1.32 Jupiter’s Moon Io Jupiter’s Moon Europa Jupiter’s Moon Ganymede Jupiter’s Moon Callisto Saturn 12 Uranus X .93 Neptune X 1.23 Pluto X .067 Part B: How far could you jump on other planets and the moon? Determine how far you can jump on the Earth. To do this, place a piece of tape on the floor as a starting line. Jump as far as you can off of both feet. Have your partner mark where you land not where you end up! Measure the distance and record in the table. Do this five times, and then find the average. Jump 1 Jump 2 Jump 3 Jump 4 Jump 5 Average (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 Gravity Length (round Convert to Length on decimals to a Feet (Divide Earth whole number) Length by 12) Sun ÷ 27 Mercury ÷ .38 Venus ÷ .86 Moon ÷ .17 Mars ÷ .38 Ceres ÷ ÷ ÷ .03 Jupiter XXXXXXXXXX 2.87 13 Jupiter’s Moon Io Jupiter’s Moon Europa Jupiter’s Moon Ganymede Jupiter’s Moon Callisto ÷ ÷ ÷ ÷ .18 .13 .15 .13 Saturn ÷ 1.32 Uranus ÷ .93 Neptune ÷ 1.23 Pluto ÷ .067 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. 14 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. 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. 15 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. __________________________________________________________________ 3. __________________ orbit changed shape slightly, which threw off the orbits of _________________________________________. 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 16