Waves Light is an example of a wave, and there are many types of waves in nature. Examples of familiar waves are water waves, sound waves, and light waves (and don't forget gravity waves). Waves are always characterized by three parameters: wavelength, frequency (number of waves per second), and speed (distance over time). These properties are related by a simple expression: Speed = Wavelength × Frequency - Speed is measured as distance traveled per second. - Wavelength is the length of a wave from peak to peak. - Frequency is the number of waves per second that pass a given point. - You can rearrange the equation S=W×F to solve for any variable you want! Exercise 4: Let us find the wavelength of a typical sound wave, the "Middle C " note on a piano. The frequency of this sound wave is about 262 Hertz (Hz) or cycles per second, and sound travels at about 340 meters per second. What is the wavelength of this note? Exercise 5: A tsunami wave can travel at a speed of over 200 meters/second, with a wavelength of about 300,000 meters (m). What will be the time between peaks of a tsunami wave coming ashore on the beach, in minutes? (hint: first solve for frequency, then use that to solve for time) Exercise 6: Electromagnetic waves AlL travel at the speed of light in a vacuum, with a speed of about 300,000 kilometers per second (or 3×10^8 meters per second). What is the wavelength of an electromagnetic wave with a frequency of one billion cycles per second ( 10^9 cycles per second)? What kind of light does this wavelength correspond to?