How Can a Simple Machine Make Work Easier?

Transcription

1 How Can a Simple Machine Make Work Easier? You have learned about how energy is needed to do work and about 6 different simple machines: lever, inclined plane, wheel and axle, screw, wedge and pulley. You have also explored the forces of motion: inertia, gravity, friction, and push and pull. To show what you remember and understand, you will develop a testable question that has to do with how simple machines can make work easier. Next, plan an investigation to answer your question. Include a prediction, show that there is fair testing, explain the procedure you will follow and list the data you will collect. 1 of 11

2 Suggested Grade Span 3 5 Task You have learned about how energy is needed to do work and about 6 different simple machines: lever, inclined plane, wheel and axle, screw, wedge and pulley. You have also explored the forces of motion: inertia, gravity, friction, and push and pull. To show what you remember and understand, you will develop a testable question that has to do with how simple machines can make work easier. Next, plan an investigation to answer your question. Include a prediction, show that there is fair testing, explain the procedure you will follow and list the data you will collect. Big Ideas and Unifying Concepts Cause and effect Change and constancy Systems Physical Science Concepts Motion and forces Transfer and transformation of energy Design Technology Concept Use of tools Mathematics Concepts Data collection, organization and analysis Graphs, tables and representations Measurement Time Required for the Task 45 minutes. 2 of 11

3 Context This task comes from a districtwide final science assessment given to third graders at the end of the school year. During the course of the year, students learned a variety of concepts from each science strand: physical, earth and life. They also worked on science process skills within each unit. The entire end-of-year assessment was designed as a means to assess students learning from each science strand as well as an opportunity for students to practice answering constructed response test items. This is a skill students will need in fourth and fifth grades when they will be asked to answer constructed-response items on standardized statewide assessments in math, writing and science. This assessment was also developed to provide the school district with science data about learning, teaching and the science curriculum. The goal of the school district is to ensure that all students have equal access to high-quality science instruction and learning. In the physical science strand, students investigated each of the six different simple machines: lever, inclined plane, wheel and axle, screw, wedge and pulley. Students learned how energy is needed to do work and that work is defined as moving an object to a new location. During the course of these investigations, students also explored the forces of motion: inertia, gravity, friction, and push and pull. Throughout this strand, students practiced a number of science process skills, such as developing testable questions, making predictions, planning and conducting investigations, controlling variables, collecting/recording/analyzing data, drawing conclusions, and communicating results. What the Task Accomplishes This task serves three purposes. First, it will assess students understanding of at least one simple machine and the work it does. Second, it requires students to apply knowledge of the scientific method to raise a testable question about simple machines. Finally, the task will assess students understanding of the scientific method and their ability to design an investigation on their own. How the Student Will Investigate This particular task does not ask students to perform an actual investigation. Rather, students need to show evidence of their understanding of the process skills needed to plan an investigation with a simple machine. Before the actual overall assessment was given, teachers and students spent a period of time reviewing concepts and vocabulary learned. 3 of 11

4 This assessment task could be used during a unit of study on simple machines, with students actually conducting their investigations once they have experimented with each of the six simple machines. I would have the class generate a list of possible questions to test and then have students work in partners, selecting one from the list to investigate. Observations and questioning of students while they conduct investigations are also important aspects of performance assessment. Interdisciplinary Links and Extensions During the physical science strand, many teachers integrated other subject areas, such as reading, writing, art, math and social studies. Some language arts and social studies examples are shared on the next page. Language Arts and Social Studies Students in many classes wrote and illustrated big books for younger children about the simple machines studied and how they are used in everyday life. Many classes also researched inventions and inventors. Some good children s books about simple machines and inventions include: Machines at Work by Byron Barton Way Things Work, by David Macauley Making Things Move, by Neil Ardley Stories Behind Everyday Things, by Jane Polley and Peter Chaitin Inventor's Workshop, by Alan J. McCormack Teaching Tips and Guiding Questions We spend plenty of time reviewing beforehand, especially any difficult vocabulary. Make sure that students truly have a conceptual understanding of the words and ideas and their relationship to the real world. For students who do not read on grade level, assistance was given by reading aloud each question of the assessment. For students who struggle with writing, the teacher was able to scribe their answers on the assessment (exactly as dictated by the student). During the review period, teachers might ask some of the following questions: What are the six simple machines? Can you give some examples where we might find some? How are they alike? How are they different? Do you use any of these in your daily lives? at home? at school? What do we mean by the word work when we are using simple machines to do work? How does a simple machine make work easier? What could you say about the amount of force needed to do work with and without a simple machine? 4 of 11

5 What are important qualities of testable questions? What questions might you raise about simple machines? How would you test your question? What steps would you include? What is fair testing? Why is it important? What are some things that you might have to control/keep the same? How will you know what data you need to collect? How do data help you to draw conclusions? Concepts to be Assessed (Unifying concepts/big ideas and science concepts to be assessed using the Science Exemplars Rubric under the criterion: Science Concepts and Related Content) Physical Science Motion and Forces; Transfer and Transformation of Energy: Students observe that simple machines enable us to move an object from one location to another and that simple machines can make work easier. Students investigate the relationships of energy, inertia, gravity, friction, and push and pull with regard to doing work. Students use the terms inertia, gravity, friction, and push and pull appropriately. Students are able to describe their relationship to simple machines, using prior knowledge. Design Technology Use of Tools: Students observe that tools extend the ability of people (to make things, to move things, to shape materials). Scientific Method: Students understand that by making a graph or table of measurements, they can determine patterns and/or changes that are happening (change and constancy). Students observe and explain reactions when variables are controlled (cause and effect). Mathematics: Students collect, organize and analyze data and can use graphs, tables and representations appropriately. Student use precise measurements. Skills to be Developed (Science process skills to be assessed using the Science Exemplars Rubric under the criteria: Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data) Scientific Method: Developing testable questions, making predictions, planning and conducting investigations, controlling variables, collecting, recording and analyzing data, drawing conclusions and communicating results. Other Science Standards and Concepts Addressed Scientific Method: Students raise questions, predict, plan investigations and control variables. Students explain phenomena in the physical world. Scientific Theory: Students look for evidence that explains why things happen. 5 of 11

6 Physical Science Motion and Forces: Students design investigations to observe and record the effects of forces that impact motion. Students observe that forces do not reside within objects but are caused by interactions between objects and that forces (such as gravity) can act at a distance and cause objects to be pushed or pulled. Physical Science Transfer and Transformation of Energy: Students understand that energy is needed to do work and that there are two types of energy: potential and kinetic. The Designed World: Students observe that tools extend the ability of people (to make things, to move things, to shape materials) and that manufacturing requires a series of steps and, depending on the task, careful choice of materials based on their characteristics. Suggested Materials For this assessment task, students will need only the assessment and their pencils. Possible Solutions Students will develop a question that is scientifically testable and that has to do with a simple machine and the work it does. The prediction should relate to the testable question. The planned investigation should find the answer to their question and include all variables they will control and the data they will collect. Students will use appropriate science vocabulary and their question, prediction and procedures should reflect understanding of the science concepts and the process of fair testing. Task-Specific Assessment Notes Novice This student s solution is incomplete and lacking in details. The student attempts to develop a testable question, but this question would be difficult to actually investigate as written. The student does include a prediction that relates to the question, but there are not any procedures. The student does not indicate a link between the pulley as the simple machine and a flagpole. The student work indicates little understanding of concepts or the scientific process. Apprentice The student does include a testable question but does not indicate which simple machine (inclined plane) will be used. A prediction is included, but again there is no reference to which simple machine will be used. The student indicates vaguely, through writing and drawing, a procedure that will use a spring scale and an inclined plane with two different surfaces. There is no specific reference to fair testing or controlling variables. The student s use of a T-chart to show data (this data came from an earlier investigation) and of a scale to measure the effect of force indicates some understanding of scientific process and of the concepts being assessed. However, the data chart does not clearly indicate what the data measured. 6 of 11

7 Practitioner This student s solution is complete, including a testable question that relates to how a specific simple machine can make work easier. The prediction relates to the testable question, and the procedures are clear in how the data will be collected. The student includes what variables will be controlled, although the control procedure (e.g., how the ball will be rolled each time) is not specified and could affect the results. The student s work indicates understanding of the scientific process, and the question and prediction show understanding of how simple machines work. Expert This student s solution is complete and detailed. The student includes a question that is clearly stated and can be tested. The prediction relates directly to the question. Procedures are clear and include each step necessary to test the question. The student clearly indicates what data will be collected and all variables to be controlled. Student work demonstrates conceptual understanding of how simple machines can make work easier. 7 of 11

8 Novice 8 of 11

9 Apprentice 9 of 11

10 Practitioner 10 of 11

11 Expert 11 of 11