Physics Homework Help - Week 3

Problem #2 in this week's homework reads:

"You ride your bike 100 m West in 2 minutes. What is your average speed? What is your average velocity?"

Solution
Step 1 - Identify variables
distance (d) = 100 m
time (t) = 2 min
avg. speed = ?


Step 2 - Identify useful equations
avg. speed = Total distance/Total time or avg. s = Total d/Total t

Step 3 - Plug variables into equation
avg. speed = 100 m/2 min

Step 4 - Solve the equation
avg. speed = 50 m/s

The only difference between speed and velocity is that velocity has a direction.

So, if the avg. speed = 50 m/s, the avg. velocity = 50 m/s WEST

The WEST direction is found in the problem.

Physics Homework - Week 3

In case you did not grab a copy of the homework from the "HOMEWORK" folder duct taped to the homework board in class, you're in luck.....here it is again. Remember, homework is DUE = FRIDAY 10/1/10. Look for some help posted tomorrow.

Physics Homework - Week 3

How are Speed and Velocity different?

Check out this video by the band They Might Be Giants. Great song that explains the difference between Speed and Velocity. The video is through Youtube so you wont be able to watch it at school.

Environmental Science Graph Practice

Alright Environmental Crew! Anyone who feels like they could use some more graphing practice and some EXTRA CREDIT can use these online resources below. For each x-y line graph you make you will earn 5 Extra Credit points. Thats equal to 1 homework assignment per graph!!!! O.k. here is the info...

1) Guidelines for making graphs
This PDF document walks you step-by-step starting with the data in a table to a finished X-Y line graph.

2) Checklist for Making a Graph
This PDF document contains a checklist that you can follow while building your own X-Y line graph to make sure you don't miss any parts.

3) Sample Data for Line Graphs
This is the PDF document that contains the data in tables you need to transform into an X-Y line graph. Again, for each graph you make = 1 homework assignment.

Let the graphing begin!

Metric Conversion Help

Hey everyone! Lets go through problem #15 on the "Metric Mania" worksheet.
Problem: Conversions
5 L = _______ mL

So we need to figure out how many milliliters (mL) are in 5 Liters (L).
Step 1: Starting at Liters (the base for volume), count the number of "steps" or "jumps" to "milli".
Base --> Deci --> Centi --> Milli = 3 steps DOWN

Step 2: Since were going down the steps, we move the decimal point to the RIGHT. We move the decimal the # of "steps" or "jumps", which is 3 in this case.
5.0 L --> 50.0 DECILiters --> 500.0 CENTILiters --> 5,000 MILLILiters (mL)

Step 3: You have your answer = 5,000 mL, but double check your work. Make sure you have the correct number of "steps" or "jumps" and that you moved the decimal in the correct direction.

If you want to ask more questions, please leave a comment in the "Post a Comment" space below. Dont forget: QUIZ TOMORROW (FRIDAY 9/17)

Homework Week 2 (9/13 - 9/17)

Environmental and Physics Students -
Your homework for this week is to make sure you complete the "Metric Mania" worksheet you got today in class (9/14) and the "Are U Nuts?" worksheet you will get tomorrow in class. Homework is due FRIDAY! If you forget/lose your worksheets, here they are to download...

Metric Mania
Are U Nuts?

I'll post help/answers to some problems tomorrow, so be on the lookout..

How big is that bread box?

What comes to mind when you hear someone describe something as "bigger than a bread box"? Firstly, I suppose you have to know what a bread box is, which most homes probably don't store their bread in these devices from the 1950's anymore. Forgetting the box though, most us can image how big a loaf of bread is. So anytime we attempt to describe the size of objects using other objects as references, such as the bread here, we make an assumption that 1) everyone knows the size of a typical loaf of bread and 2) that size doesn't change very much from person to person. This technique may work great for explaining most of the day to day objects we can visibly see, but what about really, really small objects or really, really big objects? What is our reference object?

The reality is, we don't have reference objects for really small objects like red blood cells, viruses and atoms. We can't see those objects with our naked eyes so it's difficult to image just how small they truly are. The same is true for incredibly large objects like planets, stars and even other galaxies. So how can we come to a point where these usually "invisible" objects become visible? We need a SCALE...

A scale or magnitude of size allows us to discuss very small and very large objects using units of measurement that we use for measuring objects that we can see with our own eyes. For example, an average sheet of paper is about 0.1 mm thick. If you lined up 1 million (1,000,000) atoms in straight line, that would roughly equal the thickness of that piece of paper. The ability to make comparisons like this help us image just how big or small everything around us is.

Check out this site (click "PLAY" after it loads) for an amazing comparison of objects from the extremely small to the impressively large.

Welcome Students! I hope you had a good first day. Don't forget to personally sign and have your parent/guardian sign both the syllabus and safety contract and return it by Friday (9/10) for Homework. If you lose your copy, you can download and print the syllabi and safety contract below:

Physics-Chemistry Syllabus

Environmental Science Syllabus

Safety Contract