Getting to Know Newton

Transcription

1 Introduction Overview This first program introduces students to the idea of motion, and the forces that start the movement of an object. Students are introduced to Isaac Newton who is best known for the three laws of motion. These laws are the basis for explaining the physical world. Students investigate Newton s First Law which states that a resting object remains at rest until a force acts on it; and a moving object continues to move in a straight line until another force acts on it. Students investigate ways to make objects move. Students also explore the invisible force of gravity and its effects on objects. They are introduced to the newton spring scale and measuring the amount of force required to move an object. Big Idea: Force is a push or pull which causes a change in motion. Purpose For Students to Do. Discuss and investigate forces that can be used to make objects move. 2. Measure and compare the effects of gravity on objects. 3. Explore the measurement of force with the newton spring scale. For Students to Know. can be described. 2. Force causes a change in the motion of an object. 3. Forces can be measured and compared. Materials and Preparation Kit Materials toy trucks spring scale cardboard pieces Teacher Provided Materials small nonbreakable objects meterstick or cm rulers books to construct ramps by the Los Angeles County Office of Education Note: Students may have ideas for objects to use in the investigations! Duplication Student Activity Sheets, pages :6, :0 Getting Ready for the Program Students should be familiar with the newton spring scale before this program. Demonstrate how to calibrate, use and read the spring scale. To calibrate the spring scale, use the nut and bolt at the top of the spring scale. Hold the spring scale at eye level. Turn the nut until the edge of the wide, flat top of the indicator inside the clear plastic tube is level with the zero mark on the N (newton) scale. To use the spring scale, attach the object to the hook. Hold the spring scale securely by the metal loop at the top. Slowly lift or pull the object. To read the spring scale, observe the mark with which the wide, flat top of the indicator is level. Record the measurement in newton (N) units. Program :

2 FYI... Isaac Newton was born in England and studied at Cambridge University. He wondered about why objects fall, the motion of the moon, and a powerful force called gravity. His laws of motion are the foundation of explaining our physical world and the universe beyond. Science: A Historical Perspective Students might research Sir Isaac Newton to find out more about his life and his scientific theories. Have them also research Galileo Galilei and make comparisons between these two incredible scientists. Focus Question: How has the work of these scientists affected your lives? Advance Preparation Review viewing activity descriptions in detail. Collect and organize materials as described below. Try the activities yourself! Viewing Activity # None Required Viewing Activity #2 Have common small to medium size objects available for student pairs to explore. Objects should not exceed a weight of 2 pounds. Suggestions: books, staplers, boxes of crayons or chalk, water bottles, juice cartons. Viewing Activity #3 Have books available for students to use in the construction of the ramps. Literature Connection Branley, Franklyn. Gravity is a Mystery. Harper, 986. Cobb, Vicky. Why Doesn t the Earth Fall Up? And Other Not Such Dumb Questions About. Dutton, 989. Sir Isaac Newton by the Los Angeles County Office of Education Program :2

3 Outline Notes Viewing Activities: Let s Do Science! Discussion: Meet Sir Isaac Newton Students discuss how asking questions, sharing ideas, and searching for answers are related to science. They are introduced to Isaac Newton and how his theories of motion were developed. (Viewing Activity #, page :4) Hands-On: Move It! Students explore Newton s First Law of. Students investigate and compare ways to make objects move. They discuss their observations in the classroom. (Viewing Activity #2, page :5) Hands-On: It s the Gravity of the Situation! Students explore the effects of gravity on common objects. They investigate how gravity interacts with a toy truck and ramp system. (Viewing Activity #3, page :7) Post-Viewing Activity Hands-On: Measuring Forces Students practice using a newton spring scale to measure the amount of force that is acting on an object. They gather, discuss, and compare the data. (Post-Viewing Activity, page :9) Follow-Up Activity: Keep Doing Science! What s Stopping It? (Electronic Classroom) Check out the Electronic Classroom for additional activities and resources! Hands-on Materials Transparency Caution: Do not try this at home! Activity Sheet by the Los Angeles County Office of Education Program :3

4 Viewing Activity # Discussion: Meet Sir Isaac Newton Description Students are introduced to the famous scientist, Sir Isaac Newton, and the idea that a question is the foundation of the scientific endeavor. They find out about Newton s life and the importance of questioning in the development of his theories about objects and motion. Materials None required Leading the Activity The studio teacher welcomes and asks students to think about a question involving the movement of an object. Encourages them to consider how they might find out the answer to the question. Introduces students to Sir Isaac Newton who shares a brief explanation of his life and his work. The classroom teacher facilitates the activity. Procedure. Share your question with a partner. 2. Discuss how you might find out the answer to your question. Share ideas and questions in the Electronic Classroom, by or fax! Teacher 2 Teacher Questioning is at the foundation of doing science. The idea of students posing questions related to the science concepts is important in the science learning experience. This process of inquiry is a fundamental component of the National Science Education Standards (NSES). Students should have opportunities to develop an understanding about scientific inquiry and develop the abilities to do scientific inquiry. To find out more about inquiry learning take a look at the NSES document, or go to the link provided on the TEAMS home page, Sir Isaac Newton by the Los Angeles County Office of Education Program :4

5 Viewing Activity #2 Hands-On: Move It! Description Students explore ways to move common classroom objects (books, box of crayons or chalk, pencil, crayon, chalkboard eraser, water bottle, juice or milk carton, etc.) across the desk. They discuss, record and compare their observations and results. Materials per student pair source 2 common objects classroom per student activity sheet page :6 Leading the Activity The studio teacher introduces and describes the activity. Challenges students to brainstorm ideas to answer the question: How can you make things move? Invites students to explore their ideas for moving common objects. Discusses the explorations and the methods used to move the objects (pushing by hand, blowing, magnets, etc.) Which method was easier? Which was more difficult? Encourages students to see the similarities and differences in the results, and discuss reasons that might contribute to their ideas. The classroom teacher assists the students as they explore the ways to move the objects and record their results. Facilitates discussion. Procedure. Discuss and explore ways to move the objects across the desk. 2. Record ideas and results of activity. Write the name of each object, record the force used to move the object (push or pull), and record the results. Teacher 2 Teacher There are essentially two types of forces that can affect the movement of an object a push or a pull. The push or pull, however, may be exerted in a variety of ways. The object can be manually pushed or pulled, or the force can be applied in other ways, for example, by gravity, friction, or magnetism. The "Move It" activity allows students the opportunity to explore Newton's st Law of. They investigate the forces that cause objects to move and begin to see that movement stops or changes when forces are unbalanced. It is important at this time for students to observe and recognize this idea rather than memorizing Newton's st Law of by the Los Angeles County Office of Education Program :5

6 Student Activity Sheet Viewing Activity #2: Move It! A. Choose two objects to move. Record the force used to move each object. Observe and record what happens. Object Force Used What Happened? 2 B. Record your ideas.. Which object was easiest to move? Why do you think so? 2. Which object was the most difficult to move? Why do you think so? 3. Did any of the student pairs apply different forces to the same object? Describe the force and results. 4. Which forces move the objects faster or farther? Why do you think this happened? by the Los Angeles County Office of Education Program :6

7 Viewing Activity #3 Hands-On: It s the Gravity of the Situation! Description Students have investigated forces that they can apply to make objects move. In this activity they explore the invisible force of gravity and its effects on common objects. They use a toy truck and ramp system to investigate comparisons of the effects of gravity on the movement of the truck. Materials per student group source toy truck kit cardboard piece kit - books (to support ramp) classroom meterstick classroom per student activity sheet page :8 Leading the Activity The studio teacher introduces and describes the activity. Asks students to think about gravity and discuss their ideas. Gives a brief explanation of gravity and the force it exerts. Challenges students to investigate the effects of gravitational force on the toy truck and record their observations. The classroom teacher assists students in their explorations. Asks questions to guide their thinking. Facilitates discussion and sharing of data and results. Procedure. Construct the ramp system. To adjust the height of the ramp system, add or remove books. Measure the height of the ramp system from the top edge to the bottom of the books. 2. Discuss and record ideas on the relationship between the distance traveled by the toy truck and the height of the ramp. 3. Decide on the most consistent method to release the truck on the ramp by the Los Angeles County Office of Education 4. Follow directions for activity. 5. Record and discuss ideas, observations, and results. 6. Design a graph or chart to illustrate results. Teacher 2 Teacher When the toy truck is at rest on a desk, forces are balanced. Gravity is causing the truck to push down on the desk, and the desk is pushing up on the truck. In order to move the truck, another force must be applied. If the truck is placed at the top of an incline, however, the force of gravity acts on the truck to pull it down the ramp. The height of the ramp system affects the motion of the truck and the distance it travels once it leaves the bottom of the ramp. Students can chart and graph these results in a variety of ways to observe comparisons and patterns. Range of Results The release of the truck from the top of the ramp system is critical to the investigation. The manner in which the truck is released and the point at which the truck is released should be as consistent as possible to yield valid data. Student groups are challenged to decide what method they will use to release the truck that will reduce the variability. Placing a ruler in front of the truck bumper and lifting it to release the truck is a method that reduces the chances of imposing another force (push) on the truck. Where the truck is released on the ramp is another variable that can impact the results. Student groups should consider how to most accurately identify the consistent placement of the truck for each trial. For example, the back bumper of the truck is even with the edge of the top of the ramp. Students might also consider how the length of the ramp affects the results and explore this challenge after the program. Program :7

8 Student Activity Sheet Viewing Activity #3: It s the Gravity of the Situation! A. Recording Ideas.. How will the height of the ramp system affect the movement of the toy truck? 2. How will the height of the ramp system affect the distance the truck travels from the bottom of the ramp? B. Recording Observations Ramp System Distance Truck Other Observations Height (cm) Traveled (cm) 5 cm 0 cm 5 cm C. Predicting and Testing How will a 25 cm ramp height affect the movement of the truck and the distance traveled? Predict, test, and record your results. Predictions Observations Distance Traveled Description of Movement D. Designing a Graph and Making Conclusions On a separate sheet of paper, design a graph to show the results charted in Parts B and C. Write a statement about the relationship between the height of the ramp, the distance traveled, and the force of gravity by the Los Angeles County Office of Education Program :8

9 Post-Viewing Activity Hands-On: Measuring Forces Description Students practice using a spring scale to measure the amount of force that is acting on an object. They gather, discuss, and compare the data. Note: Your students will need to be familiar with the use of the newton spring scale before this activity. (see page :) Materials per student group source 3 pcs string ( meter lengths) kit spring scale kit meter stick classroom per student activity sheet page :0 Leading the Activity Show the newton spring scale to the students. Demonstrate its calibration and use. Invite each student to select an object to use in the activity. Ask students to predict which object in their group will take the most newtons to lift, arrange the objects from most to least force required to lift, and record ideas. Discuss the explorations and methods. Encourage students to lift each object using the spring scale. Facilitate and assist students with the measuring process and recording of results as needed. Discuss and compare findings. Procedure. Think about and discuss ideas: How much force will it take to lift your object 00 cm? 2. Record ideas. 3. Attach the string and the spring scale. 4. Lift each object with the spring scale until your hand reaches 00 cm. 5. Measure the newtons required to lift each object. 6. Record the data. 8. Compare the actual results with your predictions. Share results and conclusions. Range of Results The forces that affect the movement of objects can be measured with a spring scale in newton (N) units. The accuracy of the spring scale measurement might vary based on calibration, how the spring scale is held, or the manner in which the load is picked up. The scales should be calibrated to zero, with no load attached. The spring scale should be held vertically by the metal loop at the top to carefully, and slowly, lift the load. Getting Ready for Next Time: What forces put a rollercoaster in motion? by the Los Angeles County Office of Education Program :9

10 Student Activity Sheet Post-Viewing Activity: Measuring Forces A. Prediction How much force will it take to lift each object 00 cm with a spring scale? Record the data. Object Predicted Force (N) Results (N) B. Compare Results Arrange the objects in order from the one requiring the most force to the one requiring the least force to lift. Most Newtons Least Newtons Your Conclusions. What is the spring scale measuring when the object is lifted? 2. What forces are you working against when you lift the object? by the Los Angeles County Office of Education Program :0