Color Mixing

The colors red, green, and blue are classically considered the primary colors because they are fundamental to human vision. Light is perceived as white by humans when all three cone cell types are simultaneously stimulated by equal amounts of red, green, and blue light. The complementary colors (cyan, yellow, and magenta) are also commonly referred to as the primary subtractive colors because each can be formed by subtracting one of the primary additives (red, green, and blue) from white light. For example, yellow light is observed when all blue light is removed from white light, magenta forms when green is removed, and cyan is produced when red is removed. The color observed by subtracting a primary color from white light results because the brain adds together the colors that are left to produce the respective complementary or subtractive color.

Home Energy Lab Update

Previously discussing the home energy lab I discussed ways that I could help my family reduce our power use. I have been collecting data over the past month and now that it is all collected I can see what worked for us and what didn’t. One of the biggest problems faced while doing this lab was the fact that I am rarely home. It is difficult to calculate all the electricity that my family is using and the amount of time they are using the appliances while I am not home. Although I had asked of them to work with me on this in order for this data collection to go smoothly, I do not have control of what they all do. Collecting the data for this lab was difficult to do because during the week I leave home early in the morning and don’t return until later in the evening. 

Sound Waves, Doppler Effect, Sonic Boom

The Doppler effect causes the received frequency of a source (how it is perceived when it gets to its destination) to differ from the sent frequency if there is motion that is increasing or decreasing the distance between the source and the receiver. This effect is readily observable as variation in the pitch of sound between a moving source and a stationary observer. If a moving source of sound moves faster than sound, the source will always be ahead of the waves that it produces, which is called a shock wave. A sonic boom is the sound associated with the shock waves created by an object traveling through the air faster than the speed of sound. Sonic booms generate enormous amounts of sound energy, sounding much like an explosion.

How do waves form and break?

Wind is responsible for waves. As wind rushes up along the water, the friction causes ripples. Wind continues to push against these ripples in a snowball effect that eventually creates a large wave. Essentially, this action is a transfer of energy from the sun to the wind to the waves. As a swell approaches the coastline and comes into contact with the sea floor the waves will start to slow down. Some of the waves' energy is lost through contact with the sea floor. The shallower the water becomes the slower they move. As they slow down they have to squash together. This process is called shoaling and results in increasing wave height. The steeper the sea floor gradient the more pronounced the wave height will increase. The increase in wave height begins to occur at depths of around one half of the wavelength.

Waves Superpostion

The principle of superposition is when two waves are travelling through the same medium at the same time. The waves pass through each other without being disturbed. The net displacement of the medium at any point in space or time, is simply the sum of the individual wave displacements. This is true of waves which are finite in length (wave pulses) or which are continuous sine waves. When using the principle of superposition we determine if the wave is displaying constructive interference or destructive interference. When you send two transverse waves down the same medium in the same direction the two waves will collide and form a bigger wave which results in constructive interference. When you send two transverse waves down the same medium in different directions they will collide and become smaller which results in destructive interference.