EXPLORATIONS. EDUCATOR S GUIDE Grades 4 8

Transcription

1 EDUCATOR S GUIDE Grades 4 8

2 TABLE OF CONTENTS About this topic Connecting with the classroom Minnesota Academic Standards Resources At the museum activities Chaperone page Student pages Teacher key IN THIS GUIDE Explore force and motion in the Experiment Gallery by inviting students to take on the role of scientists as they investigate the movement of objects, changes in their speed or direction, and interrelationships between motion, force and mass. The guide begins with an exploration to find moving things and speculate about the force causing the motion. HOW TO USE EXPLORATIONS Give chaperones copies of Explorations student pages and the chaperone page Add your own page(s). Connect with your own special unit. You can use just one page or all. Choose the ones that meet your needs best. Since this Exploration is designed for a large span of grade levels, it may be most appropriate to use it in different ways with different grades. For the younger grades, plan your trip to allow students multiple motion experiences at the beginning of your unit or for application of concepts learned in the classroom. For older grades, the activities can provide concept application in real life examples. Provide extensions of museum experiences back at school, especially focusing on data patterns, further experiments, and graphing results. Components are not sequential. You can start anywhere in the exhibit If your time in the exhibits is limited, choose just a few stops. Don t try to rush your students to finish the Explorations suggestions. Some questions may leave students with more questions. Use these as the basis for aftertrip discussions or group research. Notes to the teacher INTERMEDIATE 1

3 ABOUT THIS TOPIC Newton s Cradle So who s this Newton guy and why do we have his cradle? At the end of the seventeenth century, Isaac Newton formulated three laws of motion. The cradle you see on many desks and in our Experiment Gallery allows you to play with spheres in motion and experiment with Newton s Laws. Play and experimentation with real motion are key elements of this Exploration. Because Newton s laws of motion are simple to state, but much research in recent years has documented that students typically have difficulty relating formal ideas of motion and force to their personal view of how the world works. For example, to say that a book presses down on the table is sensible enough, but then to say that the table pushes back up with exactly the same force (which disappears the instant you pick up the book) seems false on the face of it. What is to be done? Students should have lots of experiences to shape their intuition about motion and forces long before encountering laws. (Benchmarks ch4/ch4.htm#motion) Motion Everything in the universe moves. Describing, analyzing and understanding motion underlies many other topics in science. There are many topics in the study of motion, but this Exploration only touches on a few: relationships of force and motion, gravitational motion, relationships of mass and motion, moving air and a very brief introduction to waves and motion influenced by magnetic forces. This Exploration does not include breaking down motion into position, velocity and acceleration, but if your classroom study includes these, insert your own exhibit activities to reinforce these concepts at the museum. A force is a push or pull Changes in speed or direction of motion are caused by forces. The greater the force is, the greater the change in motion will be. The more massive any object is, the less effect a given force will have on it. Some objects move slowly and others move too fast for people to see them. Students need to have opportunities to observe and recognize forces that attract or repel other objects and demonstrate them. Vocabulary may get in the way if students have to struggle over the meaning of force and acceleration. Both terms have many meanings in common language that confound their specialized use in science. Notes to the teacher INTERMEDIATE 2

4 Mass and Weight The mass of an object is the measure of the amount of matter in the object. The weight of an object is the force of gravity on the object (the mass times the acceleration of gravity). Weight changes depending on many things, including what planet you re on! To focus on motion, and being able to isolate forces, mass is used in referring to the object. Gravity is the force that causes things to fall to earth. There is a gravitational force between all objects with mass. This is usually not observable unless one object s mass is much larger than the other s is. That is why we can observe this with the Earth and everything on it, since the Earth s mass is much larger. Waves This Exploration includes one activity with waves in water. The focus is on the interrelationship of the elements of waves wavelength, frequency and amplitude. In water, waves are disturbances that travel through the interacting molecules of water. Experiences with water and watching waves will give students mental images as they begin to study waves that are not as easily observable, such as sound waves or electromagnetic waves. The Teacher Key on pg. 16 includes two websites specific to waves in the ocean. Notes to the teacher INTERMEDIATE 3

5 CONNECTING WITH THE CLASSROOM Before Your Visit Do an open-ended exploration of motion with your students: How many kinds of motion do you think you could show using a ball? Find a clear area in the gym, auditorium, or yard. See how many kinds of motion you can show with the ball. Try different ways of getting the ball started, and aim it in different directions. Don t throw the ball hard it s easier to see what s happening if it s traveling slowly. Students can record observations by making diagrams that show the paths the ball took. Use some obstacles to change the way the ball moves. Make diagrams showing the different paths the ball took. What motion did the ball have when you rolled it with no obstacles in its way? What happened to the motion of the ball when it hit an obstacle? Did different kinds of obstacles affect the ball s motion in different ways? Were you able to make the ball move in a curve? How did you accomplish it? Review student activity pages for yourself and with your students. Review the schedule and your expectations for the visit with your students. Divide students into groups. Back in the classroom Review the information that students gathered at the museum by discussing the questions on the student pages. See the answer key starting on page 13. These activities are more explorations of motion and can be done before the visit, afterwards, or as small group activities. For older students, more data collection, measurements and graphing can be introduced. Make a track For each group or student: construction paper, scissors, clay, duct tape, marble Think about how you could make a marble travel in a straight line, in a zigzag, and in a circle or part of a circle using the materials listed. Draw a diagram of a track that you could build to show these motions. Make your track with the materials. Cut out construction paper shapes and attach them with clay or duct tape to the top of a table. You may also want to use clay for part of the track. Test your track with a marble. How can you make the marble start moving? How can you make sure it stays in motion? Record your observations. Experiment with the track until the marble shows straight-line, zigzag, and circular motion. Think about what you did to keep the marble in motion? What did you have to do to the track to change the marble s straightline motion to zigzag motion? What did you have to do to the track to change the marble s straight-line motion to a circular motion? Notes to the teacher INTERMEDIATE 4

6 Make a parachute For each group or student: a plastic grocery bag, scissors, tape, thread, 3 paper clips and a ruler. Cut a 30 cm square from a plastic grocery bag. Cut four lengths of thread, each about 30 cm long. Tape one end of each piece of thread to each corner of the plastic square, and tie the other ends together. Attach three paper clips to the thread. This is the parachute. Hold the parachute up high in one hand and then drop it. Have a partner cut a hole about 5 cm wide in the top of their parachute. Then drop both parachutes at the same time. Take the paper clips off the parachute without the hole. Drop the paper clips at the same time that your partner drops the parachute with the hole. Think about what might have pushed against the falling parachute to change its motion? Was there a change in the falling motion of the parachute when it had a hole cut in it? If so, why? What do you think would happen if you dropped the parachute folded up? How fast would it fall? Try it! Try some magnet activities Gather magnets you may have in your classroom, or ask students to bring some from home. Set aside free exploration time to investigate what happens when magnets are put together. Group students into groups of 4. Each group should have a minimum of 4 magnets. Groups can generate as many magnet observations as they can. Share observations with the whole class. (Caution: Do NOT place magnets on computers, monitors, television screens, computer disks, videotapes or tape cassettes.) Inexpensive magnets are available at Radio Shack, Fleet Farm and often at Ax Man. Test your magnets: (Ask students to make a chart summarizing their results.) For example Item tested Results What do magnets attract? Try coins, school supplies, desks, chairs, floor. Put a magnet on a string. What happens when brought near another magnet? Does a magnet work through a solid? (paper, cardboard, book) Does a magnet work through a liquid? (water) Can a magnet change an object's direction? Does it have to touch the object? Hypothesize: How does a magnet push or pull an object? Notes to the teacher INTERMEDIATE 5

7 MINNESOTA ACADEMIC STANDARDS: The Science Museum of Minnesota provides a field trip destination that allows teachers and students to reinforce Minnesota Academic Standards. Use of the materials in this Force and Motion Exploration will help you link learning experiences to the following content standards. Science: Grade 5 Nature of Science and Engineering Identify and collect relevant evidence, make systematic observations and accurate measurements, and identify variables in a scientific investigation. Physical Science Identify the force that starts something moving or changes its speed or direction of motion Demonstrate that a greater force on an object can produce a greater change in motion. Grade 6 Physical Science Identify the forces acting on an object and describe how the sum of the forces affects the motion of the object Recognize that some forces between objects act when the objects are in direct contact and others, such as magnetic, electrical, and gravitational forces can act from a distance. RESOURCES: Book: Force and Motion Stop Faking It! Finally Understanding Science So You can Teach It, William C. Robertson,NSTA Press, 2002, ISBN: An easy to understand and fun introduction to the basics of force and motion. Includes Newton s laws, clear explanations of major terms and examples of major concepts. Websites: The Physics Classroom: A clear and thorough tutorial on terms and concepts, developed for high school physics students. Benchmarks On-line- Motion Benchmarks for Science Literacy, published in 1993, translated the science literacy goals in Science for All Americans into learning goals or benchmarks, includes links to research, overview of topics and specific learning goals by age level. Include many helpful suggestions about introducing terms and experiences in studying force and motion at a variety of grade levels. Fear of Physics: Speed and Acceleration For further background and an online demonstration of the elements of motion Notes to the teacher INTERMEDIATE 6

8 CHAPERONE PAGE Trip Tips Explorations Force and Motion helps students understand the how things move, what makes things move and the relationships among motion, force and the size of objects. Encourage students to play with the motion they find in the exhibits. Observing motion, noticing change and what causes changes are very important. All student pages refer to exhibit in the Experiment Gallery on Level 3. Find things that move! There are many things to choose from in the Gallery. Students should choose one to complete the investigation. HARMONOGRAPH BIG WAVE TANK AIRSTREAM Very popular exhibits with long possible wait times. Come back to these if they are very busy. They work better if students work in pairs. Questions are designed to allow exploration. Finding the right answer is not as important as looking for the right answer. It s OK for your group to work to together to decide how to answer the questions. This is a popular gallery. If one exhibit is busy, students can choose another. Look for answers If students are stuck or can t find something, ask any staff member in a blue vest or apron.? What do you think?. Draw what you learned Chaperone page INTERMEDIATE 7

9 Explore Motion in the Experiment Gallery Level 3 Find things that move! List them below: What s moving? What is making Can you see what s it move? providing the force? Circle one from your list to investigate further with a partner. How fast is it moving? too fast to see very fast fast medium slow very slow too slow to notice Describe the motion: (for example: straight, curved, zigzag) Does the motion change in direction and/or speed? Describe the force that made the motion change. Student page 8

10 HARMONOGRAPH Draw a cool design with two pendulums. What s moving here? (you should find at least 5 things that are moving) Work with a partner. One person should move the adjustable weight pendulum and draw a pattern with the weight in one position.? Compare The second person changes the position of the weight on the adjustable weight pendulum and draws their own pattern. your patterns. What do you notice? Student page 9

11 . BIG MAGNET Draw the Big Magnet here: Look at the big panel above the Magnet. Find the metal wand and the magnetic field tracer. Use them to explore the force of the magnet. Metal wand Hold it near the magnet. What do you notice? Where is the force the strongest? Magnetic field tracer Hold it near the magnet. What do you notice? On your magnet sketch, draw where the force can be detected by the tools you used. What moved in the Magnetic field tracer?? Why is there a warning about watches, credit cards and pacemakers? Student page 10

12 SURF S UP! The big wave tank What kinds of waves push a surfer to shore? Use the controls to make the best waves for surfing.. Draw the tank with your perfect wave. What control settings did you use for? Wave frequency Wave height Slope of the bottom Change the force of the wave. What did you change? How did that change the motion you observed? Student page 11

13 Small Plane Try these challenges: Make the plane fly parallel to the bottom of the case. Make the plane go as high as it will go. Put the plane on the bottom of the case. Keep track of where the settings are for each of the controls Fan speed Elevator control Plane flies parallel to the bottom of the case. The plane as high as it will go. The plane on the bottom of the case.? From your experiments, What makes the plane move? Or another way to ask the question: where s the force? How did you make the plane change its altitude? Airstream What is moving? Predict: If you put a large, light balloon over the airstream tube, would it move differently than the ball? Student page 12

14 Teacher Key: Allow 15 minutes for students to find things that move. Explore Motion in the Experiment Gallery Level 3 Find things that move! List them below: What s moving? What is making Can you see what s it move? providing the force? Circle one from your list to investigate further with a partner. How fast is it moving? too fast to see very fast fast medium slow very slow too slow to notice Describe the motion: (for example: straight, curved, zigzag) Does the motion change in direction and/or speed? Describe the force that made the motion change. Teacher key 13

15 HARMONOGRAPH Draw a cool design with two pendulums What s moving here? (you should find at least 5 things that are moving) Pendulum with fixed weight, pendulum with moveable weight, pulleys, red arm, blue-gray arm, pen, metal rods connected to the pen, etc. Work with a partner. One person should move the adjustable weight pendulum and draw a pattern with the weight in one position. The second person changes the position of the weight on the adjustable weight pendulum and draws their own pattern.? Compare your patterns. What do you notice? Answers will vary, e.g., the designs are different when: putting the weight in different places, starting the pendulums at different times, making one go faster than the other does at first. Also, they both slow down and finally stop. The interrelationship of the motion of the pendulums, as friction damps the motion, creates the patterns. The patterns can be considered a mathematical depiction of the motion of the coupled pendulums. It is another way to describe the motion. Note: Patterns take a few minutes to draw. Teacher key 14

16 . BIG MAGNET Draw the Big Magnet here: Look at the big panel above the Magnet. Find the metal wand and the magnetic field tracer. Use them to explore the force of the magnet. Metal wand Hold it near the magnet. What do you notice? Where is the force the strongest? Magnetic field tracer Hold it near the magnet. What do you notice?? On your magnet sketch, draw where the force can be detected by the tools you used. What moved in the Magnetic field tracer? The small magnet in the field tracer responds to the magnetic field in the big magnet. Magnetic force is not just between the white plates, but can be felt and shown surrounding the black encased magnet. Why is there a warning about watches, credit cards and pacemakers? The strong magnetic field (not just between the white plates) can influence the magnetic or electrical parts of these items. Teacher key 15

17 SURF S UP! The big wave tank What kinds of waves push a surfer to shore? Use the controls to make the best waves for surfing.. Draw the tank with your perfect wave. What control settings did you use for? Wave frequency Wave height Slope of the bottom The Rubber Ducky acts like the surfer. It gets pushed best by a breaking wave. That is formed when the floor of the tank does NOT slope gradually, but has a bump in the middle (board # 3). Exploring the best wave may take a long time, especially if there are many other visitors at the tank. Compare surfing results. If no one was there long enough to try many combinations, ask students to find information on waves, slope, and force. For more on science and surfing: Along the US Pacific coast, the sea floor off the coast changes very abruptly. This creates a steep slope, as the ocean rapidly becomes shallower. This causes the waves to break, away from the shore and provides surfers with radical waves. Off the coast of Hawaii, tropical reefs create a sudden change in the floor depth producing the same results. Off the US East Coast, the Atlantic Ocean s floor rises slowly towards shore. This cause waves to roll great distances and break close to the shore. Change the force of the wave. What did you change? Either changing the height (more force) or the frequency (change in force frequency) How did that change the motion you observed? Teacher key 16

18 Small Plane Try these challenges: Make the plane fly parallel to the bottom of the case. Make the plane go as high as it will go. Put the plane on the bottom of the case. Keep track of where the settings are for each of the controls Fan speed Elevator control Plane flies parallel to the bottom of the case. The plane as high as it will go. The plane on the bottom of the case.? From your experiments, What makes the plane move? Or another way to ask the question: where s the force? Moving air from the fan How did you make the plane change its altitude? Changing the speed of the air and/or changing the shape of the airplane s tail (elevators) Did the two seem related? Yes. The forces involved in flight of airplanes are complex AND interrelated.students can start to observe a complicated system of motion, forces and interrelationships. For more on flight, try this website: Ask the students to make paper airplanes and include elevators like the ones on this small plane. Does it change the motion? Airstream What is moving? The ball, a stream of air when the button is pushed. Predict: If you put a large, light balloon over the airstream tube, would it move differently than the ball? Bring a balloon or two for students to try out at the Airstream exhibit. It should react differently because of the mass difference. Try making the balloon close to the same size as the ball, then smaller and larger too. Supervise students when they are trying this. Please do not use small balls. The force of the moving air works in similar ways to the Small Plane exhibit and has similarities to airplane flight. The pressure is lower in a moving fluid than in a stationary fluid. This effect is called the Bernoulli effect. A ball balances in the stream of air from the blower. The ball is strongly held in the lower pressure stream of air, allowing it to overcome gravity forces as the airstream moves. Teacher key 17