1 / 19

COMT 391

COMT 391. Some Fundamentals. Fundamentals. The Metric System What is a “Wave” Calculations in “Decibels”. The Metric System. Based on MKS - Meters, Kilograms, Seconds 1 m is about 3 feet 1 kg is about 2.2 pounds. “Scientific” Notation.

jetta
Download Presentation

COMT 391

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. COMT 391 Some Fundamentals

  2. Fundamentals • The Metric System • What is a “Wave” • Calculations in “Decibels”

  3. The Metric System • Based on MKS - Meters, Kilograms, Seconds • 1 m is about 3 feet • 1 kg is about 2.2 pounds

  4. “Scientific” Notation • Large and small numbers are written as a number “around” 1, multiplied by ten raised to the proper power • 41,400 = 4.14x104 • 1,000,000,000,000 = 1x1012 • 0.0000543 = 5.43x10-5

  5. Try It • 9845 • 768000000 • 0.012 • 0.3 • 0.0000000004

  6. And the answers are... • 9845 = 9.845x103 • 768000000 = 7.68x108 • 0.012 = 1.2x10-2 • 0.3 = 3x10-1 • 0.0000000004 = 4x10-10

  7. Number Prefixes • Prefix designates powers of 10 •  0.000001 10-6 • m 0.001 10-3 • c 0.01 10-2 • k 1000 103 • M 1000000 106 • G 1000000000 109

  8. Try it • Convert 10000m to km • Convert 1mm to m • Convert 3mm to km • Convert 13km to m

  9. The Result • 10000m = 10km • 1mm = 0.001m = 10-3 m • 3mm = 3x10-6 km • 13km = 1.3x10-10 m

  10. Some Numbers • Speed of light: 3x108 m/sor 300,000,000 m/s or 300,000 km/s • Mass of the earth: 5.98x1024 kg • Radius of the earth: 6.38x106 m • Speed of sound in air: 343 m/s

  11. Waves A wave can be roughly defined as an organized series of disturbances traveling through space or through a medium.

  12. “Ripples” - Surface Waves

  13. At a fixed time ...

  14. At one point along the surface

  15. Measurements Amplitude (A) Number of cycles per second is frequency (f) In 1/sec = Hz Wavelength () in meters (with prefix)

  16. Types of Waves • Sound - pressure disturbance in a medium (air, water, etc.) • Surface - disturbance in the “normal” position of the surface • Electromagnetic - alternating electric and magnetic disturbances in a medium or in a vacuum.

  17. For all waves: The speed of the wave is equal to the product of the wavelength and the frequency.

  18. Some Examples • Speed of light: 3x108 m/s • Find the wavelength for each case • AC Current: 60Hz • FM Radio: 90MHz • Ka Band Satellite: 20GHz • Ultraviolet Light: 1015 Hz The speed of the wave is equal to the product of the wavelength and the frequency.

  19. Some Examples • Speed of light: 3x108 m/s • Find the wavelength for each case • AC Current: 60Hz = 5000km • FM Radio: 90MHz = 3.33m • Ka Band Satellite: 20GHz = 15mm • Ultraviolet Light: 1015 Hz = 3x10-7 m The speed of the wave is equal to the product of the wavelength and the frequency.

More Related