Once Stats completes the M&Ms and Water labs, Rob is teaching standard deviation (SD). The TI84 calculates SD. Rob thinks the kids should calculate it manually once to understand variance and just what SD is. Khan Academy has step by step instructions. Rob is using How long does it take you to drive home from school? to review mean, median, and mode, while teaching SD.
Once he finishes this activity, I would like to do the Parking Lot Biodiversity Lab. A biodiversity index examines variance in ecosystems. Another activity for the kids is constructing Population Pyramids or histograms. These two activities show kids how the stat activities are relevant to Ecology and Human Geography. This activity, Power of the Pyramids is excellent. Read the questions. When I use these exercises, we always discuss the implications of countries such as Japan or in Western Europe with low fertility rates AND countries with high fertility rates. My focus is on economic implications, not birth control or ZPG.
This census population exercise comparing states and even cities is excellent.
Friday, September 20, 2019
Statistics: Intro to Graphing Calculator
Update! Yes, we finished the M&M lab, graphed the data in a histogram and practiced several data sets! Whooooo! This seldom happens! We finished the planned lessons.
The Chemistry class meets Tuesdays and Fridays this year. Tomorrow, my husband, Rob, and I are doing another combined Chemistry and Statistics class to introduce experimental design and how to use the graphing calculator.
The Chemistry class meets Tuesdays and Fridays this year. Tomorrow, my husband, Rob, and I are doing another combined Chemistry and Statistics class to introduce experimental design and how to use the graphing calculator.
First, we're using this graphing exercise to see if the kids can enter the data into the STAT function, turn on STAT PLOT, set the range, graph the data (depth and average temperature), calculate the linear regression, and overlay the line of best fit over the scatter plot data. In other words, see if they remember our lesson from Tuesday. Maybe.
Next, Rob and I are going to do this Statistics and Probability Lab with M&Ms. He and I have 15 small cups of 50 gram samples of the candies, from a party-size bag of regular M&Ms. Most of the M&M labs use individual bags of candies for each student. The party-size bag was cheaper; so we weighed 50 g. samples before class.
We decided to have a quick discussion about experimental design, hypothesis, and controlled variables before the lab. Basically, the kids are going to predict which color M&M candy is the greatest percent in the candy sample (alternate hypothesis) or the percentages of each color are the same (null hypothesis). This article explains how two companies produce M&Ms varies slightly by company. The percentages by color are in this article--for milk chocolate candies!
We are going to give each child a cup with 50 grams of candies. They will count the number of each color candy and calculate the percentage of each color in the cup. Next each table of three kids will pool the data. Finally, we'll pool and calculate the class data. Next Tuesday, Rob is going to do two other exercises with the Statistics class, such as sampling with replacement and outliers. Once we have the class data, the kids are going to graph it in the graphing calculators and produce histograms--bar graphs by color. Yeah!
What does this have to do with Chemistry? Very little. However, it will allow a brief discussion of experimental design and introduce the kids to the graphing calculator.
Statistics: From the beginning
At the beginning of class, Rob and I switched. He monitored Chemistry and I taught Statistics how to create a stem plot or a box plot. We entered data (2,4,6,8,10,12) into L1 of Stats, graphed the stem plot, calculated one variable (1 Var) statistics and used the TRACE function on the stem plot or box plot to locate the quartiles and median. We repeated with new data (5,10,15, 20, 25, 30). The short-cut to set the Window or Range is Zoom 9 for STAT functions.
We reviewed definitions for mean, median, mode, quartile, a five point summary, box plot, examples. They drew a bar chart or histogram based on the data in the book.
We reviewed definitions for mean, median, mode, quartile, a five point summary, box plot, examples. They drew a bar chart or histogram based on the data in the book.
Apologia Physics: Motion
The kids are working on several motion labs: Ramps and Balls, Go Pro with Hot Wheels Car, and Are You Speeding? The introduction to Motion allows for experimentation. Are You Speeding? uses Pasco Spark with the motion sensor. The kids literally follow the Sparkvue lesson to learn how to collect motion data with a motion sensor.
On Tuesday, the kids did experiments with ramps and balls. (The ramps are 4x6 boards cut into one meter lengths at Lowes. The ball is a Pinkie ball.) The object was to demonstrate average speed and acceleration. They leaned one board against a book shelf. The other board was placed on the floor at the base of the first board. How could they measure the acceleration of the ball as it rolled down the ramp? We do not have a radar gun to measure the instantaneous speed at the bottom of the ramp. We approximated the top speed of the ball by measuring the time it took to cross the one meter board on the floor; the assumption being that the ball would not slow down significantly on the flat portion. After we measured the elapsed time of the ball on the one meter board on the floor, we compared that to the starting speed, which in this case was zero, got the difference and divided by the time elapsed by the ball rolling down the ramp. This was the acceleration experienced by the ball on the ramp. It is crucial that the students calculate the acceleration by dividing the change in speed by the time and include all units of measure. Acceleration is changed in speed divided by time. Therefore if they set up the calculation correctly the resulting measure is meters per second squared.
The kids used Hot Wheels track with the Go Pro Hero and the Hot Wheels car to measure the same as above. By observing the GoPro video, we could determine the speed by counting the frames of video recorded by the car covering the measured meter. It helps to put some colored tape on the beginning and end of the measured meter of Hot Wheels track so one can see the beginning and end of the measured distance. After counting the frames, one must look up the frames per second for the GoPro and convert frames to seconds. We were not able to use the motion sensor to determine instantaneous speed but they had fun trying it.
We used the motions sensor to measure a student's walking back and forth. This measures the displacement from the beginning point.
The assignment for Tuesday is to read all or module 2 and complete the on-your-own problems.
On Tuesday, the kids did experiments with ramps and balls. (The ramps are 4x6 boards cut into one meter lengths at Lowes. The ball is a Pinkie ball.) The object was to demonstrate average speed and acceleration. They leaned one board against a book shelf. The other board was placed on the floor at the base of the first board. How could they measure the acceleration of the ball as it rolled down the ramp? We do not have a radar gun to measure the instantaneous speed at the bottom of the ramp. We approximated the top speed of the ball by measuring the time it took to cross the one meter board on the floor; the assumption being that the ball would not slow down significantly on the flat portion. After we measured the elapsed time of the ball on the one meter board on the floor, we compared that to the starting speed, which in this case was zero, got the difference and divided by the time elapsed by the ball rolling down the ramp. This was the acceleration experienced by the ball on the ramp. It is crucial that the students calculate the acceleration by dividing the change in speed by the time and include all units of measure. Acceleration is changed in speed divided by time. Therefore if they set up the calculation correctly the resulting measure is meters per second squared.
The kids used Hot Wheels track with the Go Pro Hero and the Hot Wheels car to measure the same as above. By observing the GoPro video, we could determine the speed by counting the frames of video recorded by the car covering the measured meter. It helps to put some colored tape on the beginning and end of the measured meter of Hot Wheels track so one can see the beginning and end of the measured distance. After counting the frames, one must look up the frames per second for the GoPro and convert frames to seconds. We were not able to use the motion sensor to determine instantaneous speed but they had fun trying it.
We used the motions sensor to measure a student's walking back and forth. This measures the displacement from the beginning point.
The assignment for Tuesday is to read all or module 2 and complete the on-your-own problems.
Friday, September 13, 2019
Apologia Physics: What did we do today?
Today, the class reviewed terms; we spent most of the class reviewing the 'on your own' questions and answers. The kids are completing the first test at home. Tuesday, I'll go over any questions. We should be ready for Motion. I have several fun labs.
Saturday, September 7, 2019
Apologia Physics: Week One and Two
Friday, Week Two, the kids are going over their homework, the 'On your own' questions and taking a test for Module 1.
Here is an outline of the activities for Day One. First, we did this physics math pretest. It took all class period taking the test and reviewing the answers. This is important information; one of the kids did not know how to convert units. Next, the class did the Accuracy and Precision Lab and finally Bowling for Density.
This other density lab we did is It's all about Density from Flinn Scientific. The kids determine if which method, volume by displacement or volume by geometry is more accurate. The class can determine which method is more accurate by determining the density of a variety of objects and comparing the densities they derive with know values. My wife and I both use this lab for Chemistry and Physics. We use density blocks and have a set of mini cubes like these. We use household objects: toy block, marbles, small balls, cylinders, etc. The kids must use a variety of objects for the lab. Some of the objects will not fit into the graduated cylinder---deliberately! This is an opportunity to introduce percent error to the class. Below are photos of the equipment.
Here is an outline of the activities for Day One. First, we did this physics math pretest. It took all class period taking the test and reviewing the answers. This is important information; one of the kids did not know how to convert units. Next, the class did the Accuracy and Precision Lab and finally Bowling for Density.
This other density lab we did is It's all about Density from Flinn Scientific. The kids determine if which method, volume by displacement or volume by geometry is more accurate. The class can determine which method is more accurate by determining the density of a variety of objects and comparing the densities they derive with know values. My wife and I both use this lab for Chemistry and Physics. We use density blocks and have a set of mini cubes like these. We use household objects: toy block, marbles, small balls, cylinders, etc. The kids must use a variety of objects for the lab. Some of the objects will not fit into the graduated cylinder---deliberately! This is an opportunity to introduce percent error to the class. Below are photos of the equipment.
Friday, May 10, 2019
Apologia Physics: Special Topics reports, how did they go?
In April I assigned various special topics for the students to investigate and report back to the class. These topics were assigned for various reasons: to become familiar with current technology, to improve writing skills, and to practice presentation skills. This needs to be done in more classes as it appears that many of the students lack these skills!
Now on to the subjects:
How do high and low temperatures impact the range of an EV (electric vehicle)? Fortunately there is some research published on this topic. As EV's become more popular potential owners need to be aware of the impact of temperature on the power of a battery, and more importantly, the impact of running the heater or air conditioner. Depending on the range of temperature and the creature comforts in use, range could decrease 10 to 20 percent!
In their comparisons to a gasoline powered car, it was evident that many students had no idea how various components of the car worked. For example, one student claimed that running the heater would also reduce efficiency but in reality heat in the passenger compartment is created by using waste heat otherwise cooled by the radiator. My Dad showed me how many systems in the car worked, but it was easier when you could see and access the radiator, battery, spark plugs, etc. He also used this education as a way to sign up my brother and me for free labor changing tires, washing and waxing, oil changes etc.!
Operating cost comparison for an electric, gas, and hybrid car. Since these students are home-schooled and typically from large families, there is more of a practical attitude and less political correctness when it comes to the economics of electric and hybrid cars. The gas powered car was significantly less expensive to operate owing to the lower purchase price, which also resulted in lower costs for financing, insurance, and property taxes. In terms of an economic break even point, they discovered that it would take at least 8 to 10 years for the EV to be cost effective; and that only works if you do not have to replace the battery! Or in the case of many Teslas, replace the door handles which cost a grand a piece. Also, as a finance guy professionally, I do not invest where there is an expected 8 or 10 year payback!
What is an Eddy Current? An Eddy Current is easy to show. Just drop a relatively strong magnet down a copper tube. The magnet creates a magnetic field parallel to the tube. These fields create a circular magnetic field above and below the magnet, perpendicular to the tube. This charge on the bottom is the same as the charge on the bottom of the magnet. These charges repel and make the magnet fall much more slowly than it would based on just the pull of gravity. We did not find many practical uses for the Eddy Current but it was fun to discuss, demonstrate, and draw pictures of the fields.
How does a Mag Lev train work? Another example of magnetic fields in use. One has to draw a detailed diagram to fully understand where the magnetic fields are placed to make the train float above the "track" Even more interesting is how a linear motor works. By switching the magnet fields on the side of the tracks back and forth the magnets attract the train as the train approaches and repel the train as it goes away. These fields can also be used to stop the train! This is a very simplified explanation so go do your own research and look at some diagrams!
How do wireless chargers work? I am not an early adaptor by any means so at this time it looks like wireless chargers are for people too lazy to plug in their phone or tablet to charge. However when the wireless charging towers are further developed so that devices can be charged as a group meets around a conference table this would end the struggle to keep a couple dozen phones, tablets, and laptops charged during a long meeting (of which I have been in attendance for quite a few in my career in business).
Everyone had a good time presenting their topics and asking many questions of those who were presenting. We are now on round three (at least) of revisions to their written reports.
Next year we are teaching Chemistry, Statistics, and Physical Science which will include participation in a science fair. We will probably therefore offer a writing workshop at the beginning of the school year for all the students. Our library has a good course online; we will probably use that as a base.
Now on to the subjects:
How do high and low temperatures impact the range of an EV (electric vehicle)? Fortunately there is some research published on this topic. As EV's become more popular potential owners need to be aware of the impact of temperature on the power of a battery, and more importantly, the impact of running the heater or air conditioner. Depending on the range of temperature and the creature comforts in use, range could decrease 10 to 20 percent!
In their comparisons to a gasoline powered car, it was evident that many students had no idea how various components of the car worked. For example, one student claimed that running the heater would also reduce efficiency but in reality heat in the passenger compartment is created by using waste heat otherwise cooled by the radiator. My Dad showed me how many systems in the car worked, but it was easier when you could see and access the radiator, battery, spark plugs, etc. He also used this education as a way to sign up my brother and me for free labor changing tires, washing and waxing, oil changes etc.!
Operating cost comparison for an electric, gas, and hybrid car. Since these students are home-schooled and typically from large families, there is more of a practical attitude and less political correctness when it comes to the economics of electric and hybrid cars. The gas powered car was significantly less expensive to operate owing to the lower purchase price, which also resulted in lower costs for financing, insurance, and property taxes. In terms of an economic break even point, they discovered that it would take at least 8 to 10 years for the EV to be cost effective; and that only works if you do not have to replace the battery! Or in the case of many Teslas, replace the door handles which cost a grand a piece. Also, as a finance guy professionally, I do not invest where there is an expected 8 or 10 year payback!
What is an Eddy Current? An Eddy Current is easy to show. Just drop a relatively strong magnet down a copper tube. The magnet creates a magnetic field parallel to the tube. These fields create a circular magnetic field above and below the magnet, perpendicular to the tube. This charge on the bottom is the same as the charge on the bottom of the magnet. These charges repel and make the magnet fall much more slowly than it would based on just the pull of gravity. We did not find many practical uses for the Eddy Current but it was fun to discuss, demonstrate, and draw pictures of the fields.
How does a Mag Lev train work? Another example of magnetic fields in use. One has to draw a detailed diagram to fully understand where the magnetic fields are placed to make the train float above the "track" Even more interesting is how a linear motor works. By switching the magnet fields on the side of the tracks back and forth the magnets attract the train as the train approaches and repel the train as it goes away. These fields can also be used to stop the train! This is a very simplified explanation so go do your own research and look at some diagrams!
How do wireless chargers work? I am not an early adaptor by any means so at this time it looks like wireless chargers are for people too lazy to plug in their phone or tablet to charge. However when the wireless charging towers are further developed so that devices can be charged as a group meets around a conference table this would end the struggle to keep a couple dozen phones, tablets, and laptops charged during a long meeting (of which I have been in attendance for quite a few in my career in business).
Everyone had a good time presenting their topics and asking many questions of those who were presenting. We are now on round three (at least) of revisions to their written reports.
Next year we are teaching Chemistry, Statistics, and Physical Science which will include participation in a science fair. We will probably therefore offer a writing workshop at the beginning of the school year for all the students. Our library has a good course online; we will probably use that as a base.
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