Second Grade: Unit 1 Pushes and Pulls. push resistance pull motion force friction

Transcription

1 Second Grade: Unit 1 Pushes and Pulls push resistance pull motion force friction Background Information for the Teacher: Force is introduced at this age level as a push or a pull. Forces, such as gravity, are always at work around us. It is important for young children to understand the importance of pushing and pulling to the motion of an object. Motion is a change in place or position of an object. They should understand that a push moves an object away from them and a pull brings the object back. It is also possible to move objects without visibly touching them. Invisible forces such as gravity, magnetism, and air cause objects to move. The strength of the force applied to an object determines the resulting motion of that object. If the strength of the force is great enough, the object will move. The greater the force, the greater the resulting motion. The harder the push, the farther an object will move away from the force. If only a limited amount of force is used for the push, an object will remain in place or move only slightly. Friction is a force that resists the motion between two objects. A smooth surface has less friction, which allows objects to move easily and with less force. Rougher surfaces have more friction and cause an object to slow or stop. Force always has a direction attached to it. You cannot exert a force without direction. Young children know if they push on something, it will move away from them, if the magnitude of the force is great enough. It may move in a continuous path or line, straight, or move away from the straight path in a curve. They also understand that if they pull on something with sufficient force, it will move toward them. A push or pull cannot be applied without movement, unless the object is too large or heavy to be moved by the strength of the push or pull. Resistance to the force is impacted by friction, the force that acts on surfaces. Push: a force that moves an object away from the force Pull: a force that moves an object toward the force Force: energy that moves something Motion: movement Resistance: a force that opposes motion Friction: The force that pulls or resists the motion of two objects or materials that are in contact with each other

2 Activity 1: Describe what is happening in the picture. Use as many words as you can from the list above to tell what is happening. Questions for the Students: Who is pulling? Who is pushing? Is it easy or hard to move the wagon on the grass? What surface might make moving the wagon easier? Why? Which direction is the wagon moving? How could they make the wagon go faster? What would happen if the child got out of the wagon? How would the wagon move if both the children pushed from the back? Pulled from the front? As the students are discussing the picture, record their dictation, making sure the students can clearly see what you are writing. Copy what they say word for word; do not rephrase anything that they say. After the discussion has covered the questions above, read the text you wrote for the students. As you read, model fluency and help them make connections between what is said and what is written by pointing to the words one by one. Answer any questions that they may have.

3 Begin to develop the students discussion into a story format. Start with a sentence like, On a very sunny day in June, three children decided to go exploring in their wagon. Allow the students to add to the story, prompting them with sequence and possible events that include as many of the vocabulary words as possible. Once the story is completed, read it to the students in entirety. After modeling fluency, have them read the text orally and silently. This will help them develop fluency. Once the students are familiar with the story, begin to focus on the vocabulary words and their use in context in the story. Have the students complete the Knowledge Rating Scale independently.. Activity 2: Student Handout 1: Have students complete the Knowledge Rating Scale. Word Push Pull Force Motion Straight Curve Knowledge Rating Scale I can draw it I can tell you about it I can give examples of it. After the students have worked independently on the Knowledge Rating Scale, discuss each word to check for previous experience with the words and concepts. Generate discussion that allows the students to come up with a child friendly definition for each word. Discuss how the words are used in the story and how they might be used in the student s own experiences. Put the definitions on the board or word wall where students can refer to them throughout the unit.

4 Activity 3: Student Handout 2: Give One, Get One Using the visual in Activity 1, discuss with students that pushes and pulls are a type of force. The forces are causing the wagon to move in a certain direction. The source of the force is the strength of the push or pull by the children. If they push harder, with more force, the wagon will move faster. If they pull with less force the wagon will go slower or not move at all. Ask students to think of ways objects are moved by force. Remind them that visible and invisible forces cause things to move. Wind, magnets, water, people, and animals exert forces on objects. Show students the following video: Now complete the Give One, Get One activity FORCE 1. On your paper, write two words or phrases about the word FORCE. 2. Stand and find a partner. GIVE your partner one of the words word or phrases from your paper. GET a different word or phrase from your partner s paper and write it on yours. 3. Continue with three other students until you have at least five words or phrases on your paper. 4. Return to your seat and create a definition or description from the words and phrases you ve gathered. After each student has organized their words and phrases on FORCE, ask the group to share what they learned from the activity. Record their responses, answering questions and clarifying content knowledge as necessary. Lead the students to create a definition of the word FORCE and examples of how it works as a group. Review the story written in Activity 1 to see how force is used in the story.

5 Activity 4: Collaborative Summary Divide the students into two groups. After reading the definition of Friction as it is listed below, ask the Group #1 students to reread the definition and summarize what it says in their own words. Record their responses. After the summary is complete, ask the Group #2 students if they have any questions or any difficulty in understanding the definition. Record their questions. Ask the Group #1 students if they can help answer or clarify the questions. Answer any remaining questions and clarify for the group if necessary. Finally, ask the Group #2 students how they think the word could be used with the other vocabulary words on the list. Discuss how the word Friction might be used in the story from Activity 1. Finalize the story and have it ready for handout on Day 5. Friction: a force that acts between two objects that are in contact with one another. It slows or stops movement between the two surfaces that are touching. 1. Students in Group #1: summarize the definition. 2. Students in Group #2: ask questions on unclear material. 3. Students in Group #1: clarify the unclear material. 4. Students in Group #2: predict how the word/phrase will be used with the other words.

6 Activity 5: Vocabulary Diagram Resistance is any force that opposes motion. Discuss with the students forces that make various objects (cars, roller skates, marbles, baseballs, barriers, airplanes, people, water) slow down or stop. How does friction cause resistance? What would happen if there were no resistance to moving objects? Think of ways to lessen resistance, including smoother surfaces, inclined surfaces, use of lubricants like oil or butter, streamlined design and limiting weight or mass. Show the video Once students have a clear idea of the concept of resistance, have them complete the Vocabulary Diagram. Provide them with the Word Bank below. push resistance pull surface motion force straight path curve friction Student Handout 3: Have students use their own words/ideas to complete the Diagram. Draw a picture of resistance here. List some examples of resistance in this space. Resistance Write a sentence about resistance here. Write a definition in this space.

7 Student Handout 1 Knowledge Rating Scale Word I can draw it. I can tell you about it. I can give examples of it. Push Pull Force Motion Straight Curve

8 Student Handout 2 Force Write two words or phrases about FORCE. Find a partner. GIVE them one of the words or phrases from your paper. GET one of the words or phrases from their paper and write it on your paper. Find three other partners. GIVE each of them one of the words or phrases from your paper. GET one of the words or phrases from their paper and write it on your paper. Use the words and phrases on your paper to create a definition for FORCE.

9 Student Handout 3 Draw an example. List examples. Resistance Write a sentence. Write a definition.