# EM Spectrum Specifics

Today we’ll  start by taking a Quiz over types of waves and the Doppler effect.  Then we’ll review the EM spectrum with a video from NASA.  Be sure to take notes on each of the classes of EM waves in the video and their applications to help you make a poster later.

For the last part of class,  and you’ll make your own EM Spec diagram as a color poster.
You can use the EM spectrum diagram from the blue textbook: p. 70-71
Use a strip of paper from the back bench and Mr. Siedler’s colored pencils.
You’ll be graded on neatness but will also need:
• 7 classes of waves
• Wave Frequency in numbers (Hz) along a line
• Arrows showing increasing energy
• Examples of the wave source or technology that uses that class of wave
• Objects about the size of a single wave
Here is the Rubric on which you’ll be graded for the EM Spectrum Diagram.

# Not a subject to be taken lightly.

Today we will take notes on the whole EM Spectrum.  We have guided notes to help us follow but you should also take another look at the slides to make sure you didn’t miss something important!

We’ll also take another quiz on mechanical waves, and you’ll make your own EM Spec diagram.
Here is the Rubric on which you’ll be graded for the EM Spectrum Diagram.

# This Unit is Wave Better Than the Last.

This week we started on a new unit: Waves

First we started this unit with a set of slides and some demos describing waves in general.

After this we worked on measuring waves with our wave worksheets:
This is one,  this is the other.

The next class, we had some slides on how to change waves. Through changing the medium, or the relative speed of the source or what it bounces off of (Doppler)
Here are my slides:

Next we did some investigation into how dept affects the speed of water waves in a Tub.
Here’s the link to the lab.
And we ended with some homework calculating wave speed using the wave-speed equation.

Last, we used the computers to complete the assignment (HERE)
Using the Links in Mrs. Peterson’s Web-based Lesson here.

# It’s a Gas!

Our Last part of the matter unit was on 2 of the main laws on the behavoir of gasses.

Boyle’s

First, Boyle’s Law states that pressure and volume of a gas are inversely related. $P_1 V_1 = P_2 V_2.$  Boyle’s Law.

Boyle’s law happens everywhere: spray cans, air-tools, air-guns, car and bike tires. Said simply: when you squeeze a gas into a smaller space, the pressure increases (like in tires) or when you release the pressure (pressure goes down), the volume increases (like in spray cans).

Here’s a good animation of it:

Charles Law

The second is Charles’ Law: volume and temperature of a gas are directly proportional.

Said simply: as you heat a gas, it expands and as you cool it it shrinks.  This is why your bike tires are low in cold weather. It also is why the heated air in a engine cylinder makes your car’s engine run.

Here are our Notes

Below are some videos to help us understand why this happens using our kinetic model of matter.

Boyle’s Law;

Charles’ Law