Applied Force vs. Friction VSTA April 1, 2010

 1. Practice scaffolding guided inquiry with a science lesson. WORKSHOP GOALS  3Examine student work in the context of formative assessment and feedback.  2. Notebook components: introduce and practice how to incorporate them in the classroom.

INTENDED CURRICULUM FOR TODAY’S LESSON Friction is the force that opposes the relative motion or tendency of such motion of two surfaces in contact. (Sliding friction is the frictional resistance an object in motion experiences) In a controlled investigation, only one variable can be changed, and the results can be compared to a standard.

Lesson Content Goals 3. For every force required to move an object, there is an equal and opposite force caused by friction or gravity. INTENDED CURRICULUM FOR TODAY’S LESSON 2. Variables related to surface or mass can increase and decrease the force necessary to move an object. 1. In a controlled experiment, the experimental variable can be changed incrementally to see how it affects the outcome.

LESSON CONTENT GOALS 2. Variables related to surface or mass can increase and decrease the force necessary to move an object. 1.How can a variable be changed incrementally in a controlled experiment? 2.How does surface or mass increase or decrease the amount of force needed to move an object? GUIDING QUESTIONS 1. In a controlled experiment, the experimental variable can be changed incrementally to see how it affects the outcome. 3. For every force required to move an object, there is an equal and opposite force caused by friction or gravity. 3.What is friction?

ENGAGING SCENARIO Some warehouse workers at the Pepsi Bottling Plant have a problem. They need to move some large cases of Pepsi from the storage area to the loading dock. The fork lift that they use to move the cases is broken and won’t be fixed for a week. The delivery schedule will not let them wait until the fork lift is fixed. They have decided to move the cases by pulling them across the smooth concrete floor. It is about as smooth as your table top. However, they are not sure if this surface will require the least amount of force to pull the cases across. They think another surface like paper towel, wax paper or sand paper might be surfaces that will require less force to move the cases. They heard that you have used models to help solve these types of problems by conducting investigations. They need your help. They sent along some materials to help with the investigations. They need a report from you by the end of the day.

ENGAGING SCENARIO What is our problem here? What do we need to investigate? What is our problem here? What do we need to investigate?

Focus Question (What is the problem?) FIRST NOTEBOOK ENTRY “ What do the warehouse workers want us to do?” “What did they give us to help?” “What else do they want us to do?” What is the problem in this investigation?” Discuss your ideas with a partner, then write a focus question in your notebook and be ready to share.

SUGGESTED SENTENCE STARTER How can we find out …….?

PREDICTIONPREDICTION SECOND NOTEBOOK ENTRY What do we need to do to solve this problem? What did the warehouse workers provide us with to help solve the problem? Discuss your ideas with a partner, then write a prediction in your notebook and be ready to share. I think that the ______ surface will require the less force to move the cases because ______.

In order for us to design an investigation that will use a model we first need to identify the variables we have to work with. What are the variables in this system? In order for us to design an investigation that will use a model we first need to identify the variables we have to work with. What are the variables in this system?

PLANNING Select a variable that can be changed step-by- step. The variables in our system are surface, spring scale, wooden block, string to attach block to spring scale, distance you will pull the block. Decide: –what you are going to change? –what you are going to keep the same? –what you are going to observe or measure THIRD NOTEBOOK ENTRY

PLANNING Variable ChangedVariables Kept the Same _________________ will be observed or measured. Make a t-chart like this one in your science notebook to create a general plan for this experiment. THIRD NOTEBOOK ENTRY

But before you start your experiment, how will you record and collect your data? Make a data collection device based on what you said you were going to observe or measure and be prepared to share it. FOURTH NOTEBOOK ENTRY

Surface vs. Force Force Surface T1 T2 T3 Average Wax Paper Table Top Paper Towel Sand paper FOURTH NOTEBOOK ENTRY

Now that you have your data collection device you are ready to conduct your experiment. Get the materials needed to conduct the experiment. Make sure that you pull the block across the surface by using the same speed for each surface and for each trial. Record your results and draw a labeled diagram of what your did during the investigation. FIFTH NOTEBOOK ENTRY

As a group be prepared to discuss: What pattern you observed and recorded in your data?

Scientists always graph the results of their tests. The warehouse workers think that we should do the same. Bar Graphs display relationships between two variables. In this experiment you used different surfaces and measured the force needed to pull the block across the surface in Newtons

What do we call the two variables we graph on a two-coordinate graph? What other names do we use for the independent and dependent variables? Which variable goes on the x-axis? Y-axis? How can you remember which one is the independent variable?

Make a Bar Graph of your results. Look for relationships shown on your graph. Be prepared to share the graph. Optional: Can you think of a formula or pattern to explain the graph? SIXTH NOTEBOOK ENTRY

ENGAGING SCENARIO The warehouse workers like the help you have given them so far regarding the smooth floor needing the least amount of force needed to pull an object across the surface. Now they have another problem. They are wondering if it would be easier to pull one case or many cases across the floor each trip to the loading dock. They need your help. They now would like for you to design an investigation to help solve this problem. They need a report from you by the end of the day.

ENGAGING SCENARIO What is our problem here? What do we need to investigate? What is our problem here? What do we need to investigate?

Focus Question (What is the problem?) SEVENTH NOTEBOOK ENTRY “ What do the warehouse workers want us to do?” “What did they give us to help?” “What else do they want us to do?” What is the problem in this investigation?” Discuss your ideas with a partner, then write a focus question in your notebook and be ready to share.

SUGGESTED SENTENCE STARTER How can we find out …….?

PREDICTIONPREDICTION EIGHTH NOTEBOOK ENTRY What do we need to do to solve this problem? What did the warehouse workers provide us with to help solve the problem? Discuss your ideas with a partner, then write a prediction in your notebook and be ready to share. I think that as the weight (mass) of the cases increases the amount of force to move the cases will _____ because ______.

In order for us to design an investigation that will use a model we first need to identify the variables we have to work with. What are the variables in this system? In order for us to design an investigation that will use a model we first need to identify the variables we have to work with. What are the variables in this system?

PLANNING Select a variable that can be changed step-by- step. The variables in our system are surface, spring scale, wooden block, string to attach block to spring scale, distance you will pull the block. Decide: –what you are going to change? –what you are going to keep the same? –what you are going to observe or measure NINETH NOTEBOOK ENTRY

PLANNING Variable ChangedVariables Kept the Same _________________ will be observed or measured. Make a t-chart like this one in your science notebook to create a general plan for this experiment. NINETH NOTEBOOK ENTRY

But before you start your experiment, how will you record and collect your data? Make a data collection device based on what you said you were going to observe or measure and be prepared to share it. TENTH NOTEBOOK ENTRY

Mass vs. Force Force Mass T1 T2 T3 Average 0 Blocks 1 block 2 blocks 3 blocks 4 blocks TENTH NOTEBOOK ENTRY

Now that you have your data collection device you are ready to conduct your experiment. Get the materials needed to conduct the experiment. Make sure that you pull the block across the surface by using the same speed for each surface and for each trial. Record your results and draw a labeled diagram of what your did during the investigation. ELEVENTH NOTEBOOK ENTRY

As a group be prepared to discuss: What pattern you observed and recorded in your data?

Scientists always graph the results of their tests. The warehouse workers think that we should do the same. Two-Coordinate Graphs display relationships between two variables. In this experiment what were the variables you examined?

What do we call the two variables we graph on a two-coordinate graph? What other names do we use for the independent and dependent variables? Which variable goes on the x-axis? Y-axis? How can you remember which one is the independent variable?

Make a Two-Coordinate Graph of your results. Look for relationships shown on your graph. Be prepared to share the graph. Optional: Can you think of a formula or pattern to explain the graph? TWELFTH NOTEBOOK ENTRY

SHARE DATA COLLECTED Listen and discuss MAKING MEANING CONFERENCE

What is a variable? What was the relationship between the independent and dependent variables in both investigations? How can you use a two-coordinate graph to predict the force needed the to pull any amount of blocks across the table top?

Content Blast

PUSH OR PULL = FORCE

UNBALANCED FORCES

Things eventually slow down or stop moving.

FRICTION OPPOSES MOTION Friction pair= tires and road surface CAR AT REST Friction pair= grass surface and ball GOLF BALL NOT MOVING MOVING SKATES Objects stops when all forces are balanced Friction

What is friction? When you were measuring the force needed to pull the block across different surfaces, what were you also measuring? When you were measuring the force needed to pull various amounts of blocks across the tabletop, what were you also measuring?

MAKING MEANING CONFERENCE 1.I claim that the amount of force needed to pull the wooden block across the surface increased as the surface became rougher. 2. I claim that as the number of blocks increased, the amount of force needed to pull them across the table top increased. 3. I claim that a two-coordinate graph can be used to predict the amount of force needed to pull any number of blocks. 4. I claim that the amount of force needed to pull the blocks across the tabletop was equal to the amount of limiting frictional force pulling back.

I claim thatI claim this because I know thatI know this because CLAIMS AND EVIDENCE THIRTEENTH NOTEBOOK ENTRY Write two or three claims and evidence statements of your own based upon the data that we have discussed. How does the evidence support your claim? How was the evidence sufficient?

CONCLUSIONCONCLUSION Look at both of your predictions again. How did the evidence support your predictions? Do you wish to affirm or revise your predictions? Why? For each prediction complete My prediction was accurate because….. I wish to revise my prediction because… FOURTEENTH NOTEBOOK ENTRY

CONCLUSIONCONCLUSION Now write a concluding sentence using the stem: “Today I learned …. “ Or “In conclusion, ….” FIFTEENTH NOTEBOOK ENTRY

REFLECTIONREFLECTION SIXTEENTH NOTEBOOK ENTRY What if …? What really surprised me about this investigation was … ? A new question I have now is… ? I want to know more about... ? I am confused about … ? Think about the investigation we just completed. Use one of the stems below to write a reflection regarding the investigation.

ACHIEVED CURRICULUM ACHIEVED CURRICULUM (as evidence in science notebooks)

 1. Practice scaffolding guided inquiry with a science lesson. WORKSHOP GOALS  3Examine student work in the context of formative assessment and feedback.  2. Notebook components: introduce and practice how to incorporate them in the classroom.