Monday, May 5, 2014

UPDATE: Home Energy Lab

This semester, we have been continuously working on our wonderful home energy labs! Our challenge was to create a unique lab that focused on changing our lifestyles to save energy in our households and therefore, saving money on our electric bill! We started collecting data in February, so thus far, I have about two three months of solid data! I received my electricity bills for the months of February and March, but have yet to get my bill for April! Hopefully I get it before the project is due!!
For my lab, I decided to change three electricity-related habits of my family to alter in hopes of reducing my electricity usage!
1) Do nightly sweeps of the house to make sure our family is not unintentionally wasting energy!
2) Wash laundry only when you can fill the machine up to the top!
3) Reduce television time to 3 hours a day!

I made calendars for the months I was experimenting on so that I can keep track of my data! I would mark yes or no for nightly sweeps, "full" on days we washed clothes, and the number of hours for television time. This helped me understand my data and provide a conclusion! Keeping up with my original plan didn't go quite as easily as I hoped (maybe because we usually watch a lot of TV), but nonetheless, I think our family's inconsistency helped to show how the altered habits changed our electricity usage. In January, our bill was about the $210, in February, it was about $196, and in March, it was about $202. According to our bill and my calendars, February was the most regulated month regarding the changes in electricity habits in comparison to March and January.

I think data would have been clearer if I took down data and kept a calendar for the month of January without changing our habits (as a comparison month for the subsequent months).

(View from the home that is being tested)

Another tip to save energy is to study by the light of the sun! If you have the sun lighting up your study area, you don't need to use electricity!

Save energy!!

Sunday, May 4, 2014

Sound Waves, Sonic Boom, and the Doppler Effect!!

We have been covering so many things in physics recently having to do with waves!! In this post, I'll be covering sound waves, sonic boom, and the doppler effect!

Sound waves are longitudinal, sinusoidal plane waves that are perceptible by humans from about 20 Hz to 20,000 Hz. These waves can be characterized by frequency, wavelength, wavenumber, amplitude, sound pressure, sound intensity, speed, and direction.

"SONIC BOOM" sounds familiar, but what exactly is it? A sonic boom is the point where the shock waves that are created travel faster than the speed of sound "mach 1". Sonic booms occur when there is a large amount of energy at one time, resulting in a sound that resembles an explosion! This is common in planes when they are traveling very fast!!

Lastly, the doppler effect is the change in frequency of a wave for an observer moving relative to its source. For example, when a car is passing you and it's beeping it's horn, the frequency is higher when it is approaching and passing you and lower when it is receding. As the source of the wave (the car) is moving closer to the observer, the wave crests are emitting from a position closer to you, therefore, increasing the frequency. On the other hand, when the wave is moving away from the observer, each wave is emitted from a position further from you, therefore, the frequency is decreased.

We associate ourselves with sonic booms very rarely, but one of the most common times we do is when we are riding an airplane! Airplanes travel at very high speeds to where they are able to generate "sonic booms".


It's kind of hard to catch the doppler effect or sonic boom on camera! Nevertheless, here's an example! If someone was standing on the side of this road, as I approached them (traveling at 60+ mph on the highway) they would hear a high pitched, high frequency noise. Just after I passed them, they would hear a low frequency, low pitched noise. Next time you're walking on the side of the road, stop and listen for the doppler effect!