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QOTD 9/29/14. Please get your homework (Percent Error Calculations) and your blue stamp sheet out. Pick up the QOTD sheet and a ruler. Make sure the sheet goes in your QOTD section of your notebook! There will be a QOTD participation check early next week on the unit exam day!.
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QOTD 9/29/14 • Please get your homework (Percent Error Calculations) and your blue stamp sheet out. • Pick up the QOTD sheet and a ruler. Make sure the sheet goes in your QOTD section of your notebook! There will be a QOTD participation check early next week on the unit exam day!
% Error HW RECALL: error is a measure of how inaccurate a measurement is and that it depends on the size of the measurement! • A “big” error might not really matter if the measurement itself is really big • A “small” error might be VERY important if the measurement itself is very small Turn and talk (one minute) • what was your percent error for each of the 4 measurements on the homework? • What specific things could have caused you to be in error for each measurement?
% Error Answers (last page of the assignment) • (11.00 s - 10.67 s) x 100 = 0.33 s x 100 = 10.67 s 10.67 s Notice how the units cancel. There are no units in the answer! 3.09%
% Error Answers (last page of the assignment) 2. (19.81 g - 20.00 g) x 100 = - 0.19 g x 100 = 20.00 g 20.00 g -0.95%
% Error Answers (last page of the assignment) • You need to make the units match first! Convert hours to seconds! 1 hr x 60 min x 60 s = 3600 s 1 hr 1 min (3612 s – 3600 s) x 100 = 12 s x 100 = 3600 s 3600 s 0.33%
% Error Answers (last page of the assignment) 4. (1.43 g - 1.42 g) x 100 = 0.01 g x 100 = 1.42 g 1.42 g 0.70%
Learning Target • Be able to calculate the slope of a line • Describe the meaning of the units of the slope of a graph
Back to the QOTD…. Turn and talk (30 sec): What does slope mean? Slope is: • “how steep the line is” • “rise over run” • “the change in y divided by change in x” A steeper line means a greater increase in the responding variable (y axis) for the same amount of change in the manipulated variable (x-axis) In other words: steeper slope means the manipulated variable has a greater impact on the responding variable!
Turn over the QOTD sheet For those of you who haven’t had “slope” taught in math yet, here’s a quick walkthrough: (see Mr. C’s graph on the doc camera) I will be picking points off my line of best fit to plug into the equation on the “Calculating Slope” sheet.
Calculating Slope You have about 5-10 minutes to finish the “calculating slope” WS (back of the QOTD). Help your lab partners- work together! When done, please show it to Mr. C for a stamp on your blue sheet. We will debrief this in 5-10 minutes.
Calculating Slope Answers • See Mr. C’s answers on the doc camera…
Lab: Mass and Volume Exploration Turn and talk: (30 sec) : Does the mass of an object depend on its volume or does volume depend on mass? Demo: water in a beaker
Lab: Mass and Volume Exploration Pick up the Mass and Volume Exploration sheet. You have the rest of the period to finish your prelab for tomorrow. HW : finish the prelab – I will check it tomorrow Put the prelab check on your blue stamp sheet!