# prob11 - IR begins at 3 THz and visible at 430 THz. UV...

This preview shows pages 1–2. Sign up to view the full content.

Instructions Complete the following exercises in class on Thursday, June 2. Feel free to work together in groups or to consult with your instructor. These exercises are for your bene±t and need not be turned in. Make sure you understand all of the material! 1. Write down the electromagnetic spectrum in order of longest to shortest wavelength. Write it down in order of largest to smallest frequency. 2. Write down the electromagnetic spectrum in order of highest energy to smallest. Give an example of a use of each of the bands. 3. Sketch an electromagnetic wave. Explain brie²y how this wave is able to propagate without a medium. 4. A light wave has a frequency of 4.9 x 10 14 cycles/s. What is the wavelength? What color would you observe? 5. What is the wavelength (in m) of the electromagnetic waves sent out by a radio station whose frequency is 1350 kHz (note the "kilo")? Summer 2011 1 Problem Set 11 P ROBLEM S ET 11 G ENERAL S CIENCE 121 S UMMER 2011

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
6. The lowest observed radio waves have a frequency of about 10 Hz.
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: IR begins at 3 THz and visible at 430 THz. UV starts at 750 THz. X-ray begins at 3 x 10 16 Hz and gamma-ray at 3 x 10 18 Hz. Calculate the corresponding wavelengths. 7. Explain how Roemer Frst measured the speed of light. 8. How many minutes are required for sunlight to reach the earth if the sun is 1.5 x 10 8 km from the earth? 9. On a clear night, when you look out in space, you really see history in real time. Explain why. 10. Calculate how many meters are in a light year. The nearest star Alpha Proxima is about 3.5 light years away. Convert this to meters. 11. The Magellan spacecraft in orbit around Venus uses radar to map the surface. It does this by timing how long it takes a radio signal pulse emitted by the spacecraft to return. It times one signal 0.051 s to return. Another is timed at 0.050 s. What is the difference in height of the terrain? Summer 2011 2 Problem Set 11...
View Full Document

## This note was uploaded on 06/02/2011 for the course GSCI 121 taught by Professor Niculescu,m during the Spring '08 term at James Madison University.

### Page1 / 2

prob11 - IR begins at 3 THz and visible at 430 THz. UV...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document
Ask a homework question - tutors are online