8-31, today in class

HMWK: problems from yesterday's post PLUS find the slope and equation to represent the two lines we graphed in class today.

Today we:
-practiced dimensional analysis with more silly units ex. Simplify: (worms/apple)/apple , etc.
-tested the items we measured density on yesterday - do they float in water / oil? and shared results. Some groups had to re-measure their blocks as a result.
Completed labs turned in, if incomplete, finish up and get turned in by Friday. A complete lab should have:
Title
Page #
All questions answered/work shown / data complete
Correct measurements, densities, and units for the 5 items we measured.

We started a graphing activity that's mixed graph analysis, dimensional analysis, and scientific method practice. A data table was posted with heights of grass in Mr. Freeman's unwatered yard vs. Mr. Pounds's watered grass. The best type of graph to represent the data turned out to be a scatter plot graph with a line of best fit, and classes were asked to find an equation to represent each line as homework. How do you do this? First you need to find slope for each line. To do this, find two points' coordinates ( like (x,y)) that your line crosses through using your graph paper. Next, subtract the change in y values (height). This is your "Rise". Subtract the change in x values (days). This is your "Run". Find your line's slope by dividing (Rise / Run).
This slope is the "m" in the y=mx+b equation format (this is called slope-intercept form).
Finally, you need the "b" for your equation; it is the y-intercept, or the place where your line crosses the y-axis. This number should be around 44-46mm for our graph example.
Your graph's equation will be the y=mx+b equation, with your slope as the "m" and your y-intercept as the "b"

Also today - Announcement: EXAM next WED.

How will I be assessing your understandings and knowledge? See the page handed out in class today:
Unit 1 Assessment categories: (I expect you to perform well in all of the following areas)
1. Why is SI important/valuable? What are drawbacks of SI? (vs other measurements)
Use SI prefixes to represent quantities and convert between measurements:
2. Express (some measurement) in: a. (some SI unit) b. (different prefix, same unit) c. “ “
3. Determine the density of the object provided to you. Relate this item’s density/ characteristics relative to others.
4. Use tools to measure real items accurately and precisely, using appropriate SI units.
5. Design or critique an experiment using your understanding of science and experimentation.
6. Use density values to determine the volume or mass when one is unknown. Ex. Find mass of 1 liter of water.
7. Represent results from an experiment visually with an appropriate, correct, complete graph.
8. Use a graph to interpret data, explain observations, and predict other events.