Question

Answer the following question on topic shadows and waves A. We are working on the wave model of light. The idea that waves can move around on the surface of a swimming pool or a pond is obvious, partly because you can see the surface of water and the waves have large enough wavelength so you can easily see it. We can see light, but the wavelength is very very short, much shorter than our unaided eyes can see. For example, our eyes are most sensitive to green light. Green light comes in a variety of wavelengths, for example, a wavelength of about 502 nanometers results in green light. That wavelength is about 1 percent of the diameter of a human hair. Pretty short! You know that the speed of light is 300,000,000 meter/second. What is the frequency of this green light in terahertz (1 Terahertz is 1012 Hz). Give your answer to at least one decimal place (that means one place to the right of the decimal point). B. You want to know the height of a tree. You first determine that the shadow of yourself on the ground is 2.8 feet, and then measure the shadow of the tree on the ground as 31.2 feet. Knowing that your height is 5.9 feet, what is the height of the tree in feet (give your answer to at least three decimal place of accuracy) C. Which of the following statements about lunar and solar eclipses are true? Select ALL that are correct. a. When a lunar eclipse happens everyone on earth who can see the moon will see it as b. When a solar eclipse happens everyone on earth who can see the sun will see the sun as c. The only time it is safe to look at the sun with the naked eye is during a total solar d. The only time it is safe to look at the moon with the naked eye is during a total lunar e. The penumbra (rather than the umbra) of the earth's shadow is the dominating factor in a f. The penumbra (rather than the umbra) of the moon's shadow is the dominating factor in a eclipsed. eclipsed eclipse. eclipse lunar eclipse solar eclipse

Answer 1

Wave length lambda = 502 nm = 502 times 10^-9 m speed of light c = 3 times 10^8 m/s frequency n = c/lambda = 3 times 10^8/502 times 10^-9 = 3000/502 times 10^14 = 5.9761 times 10^14 hz = 597.61 times 10^12 hz = 597,61 T hz tan theta = 5.9/2.8 tan theta = h/31.2 therefore 5.9/2.8 = h/31.2 impies h = 5.9 times 31.2/2.8 = 65.743 frequency e and f are correct statements.