Richelt IS First Draft Page 2

Richelt IS First Draft Page 2

Academic
Knowledge and
Skills (AKS)
(Gwinnett
Co. Standards
Of Achievement) / D – Force and Motion
13  Investigate the relationship between force, mass, and the motion of objects (S8P3)
13a  Determine the relationship between velocity and acceleration (S8P3A)
13b  Demonstrate the effect of balanced and unbalanced forces on an object in terms of gravity, inertia, and friction (S8P3b)
13c  Define speed as a rate
13c.1  Perform calculations involving speed, time, and distance to interpret distance-time graphs
13d  Identify Newton’s three laws of motion in everyday occurrences
13e  Relate gravitational force to mass and distance
Georgia
Performance
Standards (GPS) / Major Concepts/Skills
Conceptual laws of motion and forces
S8P3 Students will investigate relationships between force, mass, and the motion of objects.
a.  Determine the relationship between velocity and acceleration.
b.  Demonstrate the effect of balanced and unbalanced forces on an object in terms of gravity, inertia, and friction.
c.  Demonstrate the effect of simple machines (lever, inclined plane, pulley, wedge, screw, and wheel and axle) on work.

Introduction:

The standards above indicate that the students should be able to demonstrate the effects of balanced and unbalanced forces; these lessons maximize the potential for an authentic assessment in which students will modify forces in order for an object to travel at the slowest velocity. The students will apply the conceptual laws of motion. With this measurement in mind, the individual lesson activities will provide ways for students to develop concepts of forces and their actions by creating the forces and observing their effects. Simultaneously, the students develop vocabulary, learn measuring principles related to forces and motion, and apply the vocabulary in context as they predict, describe, observe, summarize and synthesize. The students develop their own expressions of Newton’s laws of motion that reflect their conceptual understanding

The lessons also provide an opportunity for the teacher to scaffold students as they gain experience with inquiry in the classroom. The inquiry lessons provide a mechanism for students to expose their preconceptions or misconceptions and to resolve them and provide scaffolding so that students can gain experience with inquiry. Generalized discussion threads are also provided, but the inquiry events are flexible enough for the teacher to change them to meet the needs of his/her students. This flexibility is reflected in the titles of the segments. Intentionally, this plan is a series of lessons indicated by numbered lesson titles that do not reflect a lesson per class session or day. The conclusion of the lesson reflects a time for a conceptual check, not the end of a class segment. However, most of the plans are flexible enough for you to divide or combine them so that times meet the students’ needs. Additionally, alternate activities, modes of instruction, and modes of assessment can be substituted or intertwined with the inquiry lessons presented here so that you can best meet your students needs.

Links to references and other supporting materials such as worksheets are embedded in the electronic version. Select the link and open in order to review, modify, or print the content. Some links require internet access.

Unit Essential Question: How do balanced and unbalanced forces affect an object’s motion?

Lesson 1: How can I define position? (** There is not a lesson/worksheet for this lesson, it should not take a full period**)
·  Students will understand the terms position and distance.
·  Students will successfully measure distance in appropriate SI units.
Materials: meter sticks and metric rulers, student materials
Engage and introduce:
1.  Place a book in the front of the room. You may want to hang it from the ceiling or just place it on a table. Ask students to silently write down the position of the book in the front of the room, being as specific as possible.
2.  Have students compare their answer with a partner, was it the same, and, if not, how were the answers different?
Discussion/synthesis/summary:
1.  Have students compare their answers with someone across the room from them. Again, how are the answers different?
2.  Facilitate a short class discussion. Ask students why their answers varied. Is this important? Lead students to the idea that in order to define a position, you must first define an origin, reference, or a starting position. Then, a position is a spot a certain distance from that defined origin.
3.  Students define an origin or reference, name one, and use it to identify the position of your object (the book or another object).
4.  Students measure the distance between two positions: the opposite ends and sides of their desks using appropriate SI units and tools. *If you have not yet used measurement in an experimental setting, it will be necessary to instruct students in measurement in SI. Assess student use of the tools and their measurements as they work. If a student is not using the tools correctly or reading the measurement correctly, it must be addressed individually. This may require a mini-lesson for the class in order to address measuring concepts, including the use of decimals to record their answers. It may be appropriate to have students round to the nearest whole unit, but students must understand that they are using estimation.
5.  Students define sets of origins and positions around the room. Using their own paper, students describe two points, designating one of the points as an origin and the other as a position. Students describe each point on paper and then measure and record the measurement from the origin to the position. Students should choose at least 4 sets of origins: one that they can measure in meters, one that they can measure in decimeters, one in centimeters, and one in millimeters.
Summary and Synthesis:
·  If you choose to allow students to round and estimate the measurements, you may choose to ask students to share problems that they encountered in the measuring activity. When the problem arises, students can recognize the errors that are involved and recognize a need to have a strategy to solve the problems. This presents an opportunity to teach students to choose smaller units of measurement where estimation would not be necessary or to record their measurements using decimals. This is easy to do with a meter stick; it is appropriate to use centimeters as parts of 100 and record the number of centimeters as a decimal; i.e., 1 whole meter plus 7 centimeters is 1 meter and 7 parts of 100 or 1.07 meters while 1 whole meter plus 35 parts (centimeters) our of 100 is 1.35 meters.
·  Use a vocabulary strategy for students to record the terms that seem most appropriate for your class (i.e., select a term that you will use from the many options - origin, reference, starting position, etc.). Define this term and position. Ask the students to suggest terms that could be used to describe the measurement between the two points. Hopefully, a student will suggest distance. However, if they do not, and the terms are reasonable, students can use this as a record of their personal meaning. Explain to the students that scientists use the term “distance” to describe how far it is between two points.
Additional Assessment:
·  With a partner, have students define their positions. Have students practice measuring distances applying new or most appropriate strategies. Select measurements that would require different SI units, allow the students to choose, or mix assessments. The students must describe the two points as before. The distances must be permanent. That is, they can’t measure the distance from one person to another.
·  Have students exchange measurements and descriptions and check their partner’s work. Facilitate students measuring the distances together and comparing measurements and strategies. They need to resolve their differences or seek help from the teacher if they cannot resolve the difference in their measurements. Some minor differences will appear, but students should be able to explain them.
(2 example vocabulary organizers that students can create and add to or that teacher’s may use as a template for printing. The 5 BLOCK WORD ANALYSIS includes an example entry that can easily be deleted before teacher and student use.)
Lesson 2: How can I measure speed?
·  Students understand speed as a rate reported with two units.
·  Students will understand that if the distance traveled or the time measured to complete the travel change that the speed will change.
Materials (per group): constant velocity car or something that can travel at a constant speed, tape, meter sticks, stopwatches, calculators, graph paper (optional).
Engage and introduce:
Run the constant velocity car across the table.
Ask students to describe what they observe.
List and accept all appropriate answers.
Ask students what they could measure. Students will give many different answers, from distance and time to mass of the car, area and volume of the car, position from origin. Accept all reasonable answers again; for each measurement, ask how they would determine that measurement. As a teacher you should model appropriate questioning, asking questions that require more than a “yes” or “no” answer. Asking questions that will lead to students recognizing the importance of the measurement or how it relates to their prior knowledge. In order for students to recognize inappropriate responses, you may find it helpful to ask students to compare two or three suggested measurements.
Ask students what they could change. Again, accept all reasonable answers including things such as the color of the car. Ask students what would happen if that value would change? Would the motion of the car be affected?
Activity: Tell students that you would like them to design a lab where they change the distance the car travels (manipulated variable) and measure the time it takes to travel that distance (responding variable). (You should be able to circle these two values on the board. Time should be under what you can measure, and distance under what you can change). Also, tell students what materials they will be able to use. Have students create a procedure. At this point, you can go around and check each procedure before the students’ measure. Or, you can have students present their ideas and the class can decide if the procedures should/will work. Students should use the tape to mark off equal distances and then measure the time it takes the car to travel to each marked off distance. Also, have students record observations as they complete the lab, especially about the car.
Discussion/Synthesis and summary:
·  Have students record all of their data on the board. Have students discuss what they measured, what can this data tell them about the car? At this point you can define speed as a rate of distance over time. Students can calculate the speed that their car traveled and record it on the board using appropriate units. Students should be able to compare their data. If there are significant discrepancies between two values that should be the same, ask students what should be done. Students should suggest repeating the experiment.
·  Another option is to take students to the computer lab, or get an LCD projector and graph the data. The slope of the line is a straight line showing that the speed of the car did not change.
·  Students should update their vocabulary record that they have begun in the previous unit.
Assessment:
·  Have students write a lab procedure and a conclusion explaining how they performed the lab, their results, and the final class consensus. If problems arose, students should be able to explain these problems.
·  Additionally, students should be able to explain how they calculate a rate and the units that it should include, a distance in the numerator and a time in the denominator.
·  At this point, you may also want to have students create motion maps for their cars so that they practice non-verbal representation of constant velocity. See the reading on motion maps for details. (Open the link below.)


Lesson 3: How do you measure speed and velocity? What is the difference between speed and velocity? What variables affect velocity?
·  Students understand motion as a change in position. Students understand that all objects on Earth are in motion because of Earth’s rotation and revolution. However, an object can appear to be stationary with respect to their surroundings since this is how we often perceive motion in everyday life. The terms “at rest” and “in motion” may be used to describe these conditions.
·  Students develop concept of speed as a unit rate. (Note: Unit rates are studied in 6th grade math.)
·  Students are able to differentiate between speed and velocity
Materials: Object in the front of the room (book), science tables, 2 marbles of same mass and diameter, and 4 equal height blocks to stand the tables on. (You will need these materials for each group.)
Engage/introduce:
Identify something in the room as position A and something as position B. Ask students what must happen to get from position A to position B? (You must move). Tell students that we will define this movement as motion. Add this to the vocabulary organizer. Ask students if it is possible to change your position at all without moving? (Allow students to discuss this as pairs) Then, as a class define a change in position as motion. Have students record this on their concept map of new terms. Ask students how the motion could differ? They may come up with ideas of moving fast or slow.
Complete the Speed Inquiry Activity,
Bring pairs of tables together where the narrow ends are abutting each other. Beneath the legs of the non-touching ends, place the blocks. This creates an equal angle for each setup. Have students identify the origin (I would use the starting point) and position of the marbles. Have students make other observations of the set-up.
Have students measure the speed of each of the marbles when they release them without pushing from the top of the slope. Students will have to measure both the distance and the time.