Waves Review Waves Review m Period time it

Waves Review

Waves Review m Period = time it takes to get through one complete cycle (s) Frequency = how many cycles it gets through in 1 second (Hz) Amplitude = how high it gets above a level surface (m)

Waves Review A. What is the period of this wave? n B. What is the frequency of this wave? n

Waves Review n If you know period (T), f = 1/T If you know frequency (f), T = 1/f n Speed = frequency*wavelength n C = 3 x 108 (if not light, could also be v for speed) n

Period and Frequency n A. Calculate the period of a wave if its frequency is 4. 2 Hz n B. Calculate the frequency of a wave if its period is 3 sec.

Speed of Waves n Calculate the wavelength of a light wave with a frequency of 3. 4 x 108 – (Remember speed of light is 3. 0 x 108)

25. 1 The Electromagnetic Spectrum

Light is a kind of wave A sound wave is an oscillation of air. n A water wave is an oscillation of the surface of water. n An oscillation of electricity and magnetism creates electromagnetic waves. n

Electromagnetic Waves

Electromagnetic Waves n The major types of electromagnetic waves: – Radio Waves – Micro Waves – Infrared Radiation – Visible Light – Ultra-Violet Light – X-Ray Waves – Gamma Waves

The Electromagnetic Spectrum n Longer wavelength = lower energy n Shorter wavelength = higher energy

Check-In n List the following types of electromagnetic waves in order of increasing energy: – Visible light – X-rays – Microwaves – Gamma rays

Visible Light n Different colored light has different energies.

Speed of Light n The speed of electromagnetic waves is ALWAYS the same: “speed of light” = 3 x 108 m/s

Lesson in Calculators n For scientific notation: – – – Enter number Hit EE Enter whatever power 10 is to (use +/- first to make negative)

Lesson in Calculators n For Scientific Notation (alternate way): – – Enter number Hit the multiply key (x) Enter 10 x Put in exponent (use +/- first for negative)

Speed of Light EXAMPLE 1 speed of light = 3 x 108 m/s What is the frequency of a light wave with a wavelength of 340 nm (340 x 10 -9 m)?

Speed of Light EXAMPLE 2 speed of light = 3 x 108 m/s What is the frequency of a greenish yellow light with a wavelength of 540 x 10 -9 m?

Speed of Light EXAMPLE 3 speed of light = 3 x 108 m/s What is the wavelength of a red light with a frequency of 500 x 1012 Hz?

Speed of Light EXAMPLE 4 speed of light = 3 x 108 m/s What is the wavelength of a blue light with a frequency of 750 x 1011 Hz?

Speed of Light EXAMPLE speed of light = 3 x 108 m/s What is the frequency of a light wave with a wavelength of 340 nm (340 x 10 -9 m)?