ESSC 311 Lesson Plan. Force and Motion. Sarah Canfield Evan Gora March 13, 2012

Transcription

1 ESSC 311 Lesson Plan Force and Motion Sarah Canfield Evan Gora March 13, 2012

2 Force & Motion: Balanced and Unbalanced Forces Lesson Presenters: Sarah Canfield & Evan Gora Description of the GLCE: P.FM Describe what happens when two forces act on an object in the same or opposing directions. Lesson Title: Up, Up and Away! THE TEACHING PROCESS Lesson Overview: After completion of the lesson, students will be able to: Describe a force as a push or a pull. Explain in their own words that a change in motion is due to unbalanced forces and that no change in motion or an object at rest is due to balanced forces. List of Materials Helium Balloon Pipe-cleaners x25 for each group (cut into 2 inch segments and bent in half to form a V) Pipe-cleaner hoop Up, Up, and Away worksheet for each student Direction Of Force worksheet for each student Phase One: Engage the Learner Show class the youtube video UP! in real life to illustrate the upward force of helium. As a preassessment ask students to describe what they see happening in the video. Tell the students that they will use a helium balloon to investigate how a force acts on an object.

3 Phase Two: Explore the Concept Working in groups of 2-3 students will apply weights to a helium balloon with a hoop attached. The students will record the effect each weight has on the movement of the hoop and note the direction (up, down or stays still) the hoop moved. Activity Instructions: See attached worksheet: Up, Up, and Away Experiment #1: The students will test how many pipe-cleaners it takes to hold down a hoop attached to a small helium balloon and a hoop attached to a big helium balloon. They will record the number of pipecleaners, the direction the hoop accelerated, and why they think it takes different amount of pipe-cleaners to hold down each hoop. Experiment #2: After putting all the pipe-cleaners on the hoop the students will slowly remove the pipe-cleaners one at a time until the hoop lifts off the table. They will record the number of pipe-cleaners, the direction the hoop accelerated, and why they think there were different amounts of pipe-cleaners on each hoop when it lifted off the table. Experiment #3: Either by adding or removing pipe-cleaners the students will try to balance the upward force of the balloon with the downward force of the pipe-cleaners and cause the balloon to hover in the air. Students will record the number of pipe-cleaners, the direction the hoop accelerated, and why they think the balloon hovered. Lab Drawing Activity: Students will draw diagrams of each of the 3 balloon experiments. Using arrows to show force and direction they will label the forces in each experiment to indicate how they are thinking about force and its relationship to motion. Once the diagrams are completed, each group will share one part of their diagram stating the forces and if there is acceleration.

4 Phase Three: Explain the Concept and Define the Terms When the groups have finished their activities, ask students to make observations about the data they collected. Use the following questions to aid in eliciting responses from the students in their own words. Why do you think the hoop lifts up when it s attached to the balloon? What, if anything, happened that kept the hoop from lifting up in the experiment? By adding and removing the weights you were able to make the hoop float in the air. What do you think caused this? What is the balloon doing? What are the pipe-cleaner weights doing? After the class discussion the teacher will explain the following: That a force is a push or a pull that causes an object to accelerate (speed up, slow down and/or change direction) in the direction of its application. The terms balanced and unbalanced forces. Two forces acting on an object in opposing directions can be of unequal strength and, therefore, are unbalanced (non-zero net force). The result will be motion (starting or speeding up) in the direction of the stronger force. Ask the students to define these terms in their own words. Ask the students to give examples of when the forces were unbalanced in the helium balloon activity. That two forces acting on an object in opposing directions can be of equal strength and are, therefore, balanced. The result will be that if the object is at rest it will stay at rest and if it is moving, it will continue to move a constant speed in a straight line. Ask the students to give an example of when the forces were balanced in the helium balloon activity and what forces were balanced. Four: Elaborate on the Concept Have the students complete the front of the Direction of Forces worksheet. Then have the students flip their worksheets over and put their pencils down. The students will spend some time while thinking and looking around to come up with their own example of something that involves a push or a pull force. After 1-3 minutes ask them to draw a diagram of their example on the back of the worksheet. They should indicate the forces and their magnitude with the arrows and should indicate which way there is movement. By taking the time for them to think of an example themselves they are beginning to integrate what they are learning about forces into familiar aspects of their life. This will help with them gaining a complete and correct understanding of the concept as well as helping them personally connect with the material.

5 Phase Five: Evaluate Students' Understanding of the Concept The students will be graded on participation in the class activity and discussions, completion and accuracy of the worksheet and lab activity. Teacher should keep in mind the pre-assessment results while judging the learning progress of each student Student was engaged in the Student showed minimal en- Student shows little engage- Participation activity and actively partici- gagement but participated in ment in the activities and does pated in all aspects of class. most aspects of class. not participate in class. Student neatly completed all Student completed more than Student completed less than Completion answers on the worksheet half of the answers on the half of the answers on the and lab activity. worksheet and lab activity. worksheet and lab activity. Accuracy Student correctly answered all of the questions. Student correctly answered most of the questions. Student correctly answered less than half of the questions

6 References Direction of Force Worksheet- Youtube Video - URLs used in this lesson plan Youtube Video -

7 Direction Of Force Name: Date: Look at the pictures below. In the space below each picture: 1. Draw a line with an arrow to show the direction of the force that is being applied. Label the line with F (for force). 2. Draw another line with an arrow to show the direction of movement that results from that application of force. Label this line M (for movement). Note: Use different size arrows for strong and weak forces, smaller for smaller forces, bigger for bigger forces and the same for equal forces.

8 Up, Up, and AWAY! Name: Date: Directions: Using the helium balloon and the pipe-cleaner weights follow the instructions for each experiment below. Some answers will be circled and some will be filled in the blanks. EXPERIMENT #1: 1. While one person holds the hoop start with 0 pipe-cleaners and slowly add a single pipecleaner at a time to the hoop. Continue adding pipe-cleaners to the hoop until the hoop drops down to the table or floor. How many pipe-cleaners did it take to hold down the hoop? 2. Hold the hoop out in front of you, with the pipe-cleaners still attached, and let it go. What direction did your balloon move? Up / Down / Stays Still Why do you think it took this many pipe-cleaners to hold down the hoop? EXPERIMENT #2: 1. While one person holds the hoop put all the pipe-cleaners you have on the hoop of your balloon. Slowly remove one pipe-cleaner at a time from the hoop until it is able to float up. How many pipe-cleaners were on the hoop when it lifted up? 2. Hold your hoop out in front of you, with the pipe-cleaners still attached, and let it go. What direction does the hoop move? Up / Down / Stays Still 3. Why do you think you had to remove some pipe-cleaners but not all for the hoop to rise?

9 EXPERIMENT #3: 1. For this experiment your goal is to get the hoop to stay in the same spot in the air. While one person holds the hoop have another slowly add pipe-cleaners to the hoop. Slowly add or remove pipe-cleaners to the hoop and try to get it to float. How many pipe-cleaners were on the hoop when floated? What direction does the hoop move? Up / Down / Stays Still 2. Why do you think the hoop was able to float in the same spot? Experiment Diagrams: Below draw a diagram of each experiment. Use arrows to show how strongly or weakly the up or down motion was in each experiment. Use different size arrows for stronger and weaker forces; smaller for smaller forces, bigger for bigger forces and the same for equal forces.