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How Fast Does it Go?

Lesson Plan

How Fast Does it Go?

Grade Levels

8th Grade

Course, Subject

Mathematics, Reading and Writing in Science and Technical Subjects
Related Academic Standards
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  • Big Ideas
    Bivariate data can be modeled with mathematical functions that approximate the data well and help us make predictions based on the data.
    Degree and direction of linear association between two variables is measurable.
    Numbers, measures, expressions, equations, and inequalities can represent mathematical situations and structures in many equivalent forms.
    Numerical quantities and calculations can be estimated by using numbers that are close to the actual values, but easier to compute.
    Patterns exhibit relationships that can be extended, described, and generalized.
    Relations and functions are mathematical relationships that can be represented and analyzed using words, tables, graphs, and equations.
    There are some mathematical relationships that are always true and these relationships are used as the rules of arithmetic and algebra and are useful for writing equivalent forms of expressions and solving equations and inequalities.
    Two variable quantities are proportional if their values are in a constant ratio. The relationship between proportional quantities can be represented as a linear function.
    Data can be modeled and used to make inferences.
    Mathematical relations and functions can be modeled through multiple representations and analyzed to raise and answer questions.
    Mathematical relationships among numbers can be represented, compared, and communicated.
    Mathematical relationships can be represented as expressions, equations, and inequalities in mathematical situations.
    Measurement attributes can be quantified, and estimated using customary and non-customary units of measure.
    Numerical quantities, calculations, and measurements can be estimated or analyzed by using appropriate strategies and tools.
    Patterns exhibit relationships that can be extended, described, and generalized.
  • Concepts
    Analysis of one and two variable (univariate and bivariate) data
    Compound probabilities: addition and multiplication rules
    Linear system of equations and inequalities
    Ratio and Rates
    Variables, Expressions, Equations
    Algebraic Equations
    Categorical and Quantitative Data
    Probability
  • Competencies
    Display, analyze, and make predictions using univariate and bivariate data.
    Distinguish between independent and dependent events in order to calculate compound probabilities within real world situations.
    Write mathematical expressions and equations that correspond to given situations, evaluate expressions, and use expressions and formulas to solve problems.
    Analyze a set of data for a pattern, and represent the pattern with an algebraic rule and/or a graph.
    Analyze and/or interpret data displays and/or use them to make predictions (circle graph, line graph, bar graph, box-and-whisker plot, stem-and-leaf plot, scatter plot).
    Apply the rules of probability to compute probabilities of compound events.
    Calculate probability and/or odds.
    Make inferences and justify conclusions based on sample surveys, experiments, and observational studies.
    Represent and analyze quantitative relationships between Independent and dependent variables.
    Solve and interpret one variable equations or inequalities in real world and mathematical problems.
    Summarize, represent, and interpret single-variable data and two-variable data.
    Use combinations, permutations, and the fundamental counting principle to solve problems involving probability.
    Use measures of dispersion to describe a set of data (range, quartiles, interquartile range).

Rationale

The students will be able to apply scientific and mathematical reasoning to calculate the average speed of an object.

Vocabulary

v = d/Δt     Average Speed     Velocity     Distance      

Objectives

  1. The students will follow the procedures to conduct an experiment and record their data accordingly.
  2. The students will apply their knowledge of average speed being the total distance traveled by an object divide by total time by using the speed equation to accurately calculate the average speed of their car.
  3. The students will accurately graph their data using the distance and time interval data as well as include labels for each axis on the graph as well as title their graph.
  4. Based on the experiment and their graphs, the students will accurately describe the relationship between the elevation of the ramp and the speed of the car.  (The slope of the line on a distance-versus-time graph varies as speed changes; steeper slopes represent faster speeds).
  5. The students will complete word problems to apply their knowledge to real life situations.
  6. The students will think about and discuss what happens to the speed when the distance or the time increases.

Lesson Essential Question(s)

How are relationships represented mathematically?
How can data be organized and represented to provide insight into the relationship between quantities?
How can expressions, equations, and inequalities be used to quantify, solve, model, and/or analyze mathematical situations?
How can mathematics support effective communication?
How can patterns be used to describe relationships in mathematical situations?
How can probability and data analysis be used to make predictions?
How can recognizing repetition or regularity assist in solving problems more efficiently?
How does the type of data influence the choice of display?
How is mathematics used to quantify, compare, represent, and model numbers?
How precise do measurements and calculations need to be?
In what ways are the mathematical attributes of objects or processes measured, calculated and/or interpreted?
What makes a tool and/or strategy appropriate for a given task?

How fast did your car go?

Duration

One 50 minute period

Materials

Each pair of students needs the following:

  • 1 Ramp 4’ x 1’ (can be made of Plywood)
  • 1 meter stick
  • Masking Tape
  • Coats, Rags or other items to act as a cushion for the bottom of the ramp
  • 1 Car (a bigger car such as one used for Little People works best)
  • Textbooks used to elevate the ramp
  • A stopwatch
  • Graph paper
  • Lab Sheet (see below)
  • Pencil
  • Calculators
  • Colored Pencils
  • Enough Red and Green cups for one per partner group

Suggested Instructional Strategies

 

Students will learn a variety of skills such as conceptual understanding of data collection, graphing, and how to interpret data as well as procedural knowledge of how to organize and graph the data as well as make predictions.  In addition to the core standards, this lesson includes problem solving, reasoning and making connections.  The lesson can be adapted and enhance to meet the needs of all learners.  All instructional adaptations are marked with a yellow highlighter for below level learners and green highlighter for advanced level learners/enhancements.

 

** Before beginning the activity, use the pre-assessment below to establish which type of learner each student is.  In order to give the teacher ample time to assess learning, this pre-assessment should be administered the day before the lesson begins.

 

Advanced level learners will be able to complete all tasks accurately graphing and answering all questions in full, complete sentences with 90% accuracy.  Mark these papers with a triangle.

 

On level learners will be able to complete the questions and accurately graph the information but may not be able to find the slope of the line (75% accuracy). Mark these papers with a Circle.

 

Below level learners may need help graphing and answering questions.  They may be able to find the line of best fit, but not always.  Finding the slope of the line will need to be explicitly taught, and is not a skill yet acquired. Mark these papers with a star.

Instructional Procedures

1.  Think-Pair-Share Quick Review:  Have students answer the following questions, then go over as a class.  (This will be prior knowledge that needs to be taught prior to this lesson.  It is included in a handout below).

  1. What two pieces of information do you need to know about an object in motion in order to determine the speed?  Distance traveled and time in motion
  2. What is the definition of speed?  The distance traveled in a unit of time
  3. What is the symbol for speed?  v
  4. What units are used to describe speed?  Give an example. 

Distance/unit of time such as miles per hour

  1. What is the equation for calculating speed?  v = d/Δt
  2. If you know an object is traveling at 45 kilometers per hour, how can you determine how far it will go in ten hours?

                                         d = v X Δt = 45 x 10 = 450 kilometers

 

2.  Turn and Talk:  Suppose you wanted to figure out how fast a bicycle was going.  How would you go about it?  Come up with a specific problem solving procedure and make sure you include all of the steps.  Have groups share their procedures and determine which one is the best.  It should be:

  • Establish a starting position, xi
  • Establish an ending position, x(This establishes distance)
  • Time how long it takes for the bike to travel the distance from xi to xf
  • Use the speed equation to calculate the average speed.  v = d/Δt     

 

3.   Tell the students, in order to determine an object’s speed, we need to measure the distance the object moved, and we need to measure how long it took to move that distance.  We know how to measure distance-we use a meter tape.  So how can we measure the time it takes for an object to move?  Have the students brainstorm things we can use to measure time.

4.  Go over how to read a stopwatch.  Hours, minutes, seconds and 100th of a second.  Then have the students practice using the stopwatches. 

  • Have them stop the stopwatch close to 1 second
  • With their eyes closed, have them try to stop it at 5 seconds, etc  . .

 

5. Introduce the experiment.  Tell the students that they are working in groups to answer the following questions:

  • How long does it take your car to travel 200 cm ramp?
  • What is your car’s average speed as it travels 200 cm down your ramp?

For below level learners (stars) you can sit them all together, so if you need go over the lab procedures step by step and answer any questions  they will be sitting in proximity .

 

6.  Give the students the lab sheet. Have the students (triangle and circles) work in pairs to independently set up the experiment by reading the directions in their lab sheet.  Assist if necessary.   For below level learners, go over procedures for the experiment. Show the students the ramps and how to set it up. Also make sure the students are putting jackets at the end of the ramp in order to stop the car safely.  Also, hand out the lab rubric to remind the students how they will be graded while working in groups.  You may want to go over this specifically if you feel it necessary depending on your students.

 

7.  Divide your students into teams of four and assigned each group an elevation in multiples of 4 cm if you have eight groups, up to 32 cm.  If you have fewer teams you can use multiples of 5 cm. 

 

8.  After the students properly set up their ramps, have them time several runs with their car as it travels 200cm down the ramp and record it on their lab sheet.

 

As students are working, you can have green and red cups sitting on the desks.  If students are successfully working their way through the lab, they should have the green cup on top.  If they have a question or get stuck, instruct the to put the red cup on top and continue to try and figure out the problem, you will be around shortly. Since partner groups will be working at varying paces, there are natural stops in the lab.  When a partner group comes to that stop, they should also put the red cup on top so that I can formatively assess their accuracy up to that point in the lab.  Pairs can continue to analyze until teacher makes it around to every pair.

 

9.  When all groups are finished, gather the students and ask the following questions of the class:

  • Did your car travel the same speed the whole run?
  • How fast was it going in the beginning?  (0 cm/s)
  • How fast was it going in the middle of the run?  At the end?  (Can’t tell)

 

10.  Tell the students that it’s difficult to know how fast an object is going at any specific time because speed changes all the time.  It is not constant.  To get around this problem, we can use the object’s average speed to determine how fast it was going.  If we know how far something went, and how long it took, we can calculate the object’s average speed.    Average speed is the total distance divided by the total time needed to travel the distance. 

 

11.  For example, if I recorded times for three runs down a 10 cm ramp of 2.52 s, 2.66 s and 2.62 s, I would add them up and divide by three to find the average speed.  So 2.52 + 2.66 + 2.62 = 7.80 s.  Then divide 7.80/3 (or the number of runs) which equals 2.60 s; that is our average speed.

 

12.  Back in their groups, have the students calculate the speed for each run, then calculate the average speed of their car.

 

13.  Once the average speed for each elevation is calculated, have one speaker from each group share the data with the other groups.  Each group needs to record the average speed for each elevation in their data table.

 

14.   Finally, have the students graph the results, labeling their graph. (Time on the x-axis, Distance on the y-axis). F

For below level learners give them graph paper already labeled and numbered for them.  Graph the data together as a class. 

 

15.  After graphing the students should answer the following questions, which car went the fastest?  Which car traveled the slowest?  How do you know?  What is the relationship between elevation and speed?  (The steeper the slope the faster it goes/greater the speed).  Go over these answers as a class and discuss.

 

For below level learners complete this as a class with guiding questions such as what does the graph look like? What can you tell from the line?

To enhance this lesson for advanced level learners let them analyze the data on their own or with their partners without any guiding questions.  Then have them write a paragraph in complete sentences to describe the results.

 

16.  Ticket Out the Door:  (See handouts below)

  1. A biker rode up a 20 km hill in 2 hours and down the hill in .5 hour without stopping.  What was his average speed
    1. going up hill?  v = d/Δt = 20 km/2 h = 10 km/h
    2. going down hill? v = d/Δt = 20 km/0.5 h = 40 km/h
    3. for the whole trip?  v = d/Δt = 40 km/2.5 h = 16 km/h

       2.   When looking at a graph for speed, how can we tell who is going the fastest

                                The steeper the slope, the greater the speed


For below level learners help with the set up of this problem.  Give them the equation and help them fill it in if necessary.  Guide them through problem solving by identifying the known, unknown, set up the equation and then have them solve. This will help them when looking for speed or other unknown variables. 

                   Known:

                   Unknown:

                   Equation:

                  Solve/Work:

Formative Assessment

  • Upon completion of this activity, below level learners will be able to calculate the average speed of their car, graph data and describe the relationship between elevation and speed.  Given a graph, they will also be able to pick out which car is going the slowest and which is going the fastest based on the slope of the line. 
  • Regular education learners will be able to calculate the average speed of their car, graph data and describe the relationship between elevation and speed.  Given a graph, they will also be able to pick out which car is going the slowest and which is going the fastest based on the slope of the line.  They will also be able to complete word problems to apply their knowledge to real life situations.
  • Enhanced or advanced level learners will also be able to calculate the average speed of their car, graph data and describe the relationship between elevation and speed.  Given a graph, they will also be able to pick out which car is going the slowest and which is going the fastest based on the slope of the line.  They will also be able to complete word problems to apply their knowledge to real life situations, as well as think about what happens to the speed when the distance or the time increases.

Related Materials & Resources

See below.  The first lab sheet is for below level learners (star), the middle for regular education students (circle) and the last is enhanced for advanced level (triangle) or gifted students.  The rubric below the lab sheet will be used to evaluate the lab and how well the students work together during the activity.

How Fast Did It Go Speed Pre-Assessment.docx
How Fast Did It Go Quick Review.docx
How Fast Did It Go Lab Sheet - Star (Below Level Learners).docx
How Fast Does It Go Lab Sheet - Circle (On Level Learners).docx
How Fast Did It Go Lab Sheet - Triangle (Above Level Learners).docx
How Fast Does It Go Lab Rubric.docx
How Fast Does It Go Ticket Out The Door.docx

 

Author

Tina Warfel, IU11

Date Published

March 17, 2014
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