2. What is wave? A wave is a disturbance that moves from one place to another through a medium.

3. If you drop a pebble in the pond, a ripple spreads out in a circle around the point where you dropped the pebble. In time, the ripple will travel from the rock to the far edges of the pond. The part of water that is disturbed by the pebble does not move to the edge of the pond, but the ripple does. Anywhere along its way, this ripple can lift and drop a leaf floating on the water as it passes. The disturbance is the ripple, and the medium is the water in the pond. The energy of the pebble dropping into the water is sent in a ripple (energy in the movement) to the edge of the pond. A wave is a way for energy to travel in a medium like water or air.

4. CHARACTERISTICS OF WAVES

5. Waves are also examples of periodic motion, one that repeats itself over and over again. Periodic motion can be shown as a sine curve, as can simple moving waves.

7. A wave can be described by how big it is, its amplitude. It is the maximum displacement the wave causes.

8. The amplitude is an indication of the energy contained in the wave. The larger the amplitude, the more energy in the wave. The intensity of the wave is proportional to the wave’s amplitude squared. It tells you the amount of wave energy that crosses a unit area per second. The intensity of a wave (and its energy) spreads out over a large area.

9. Wavelength describes the distance from peak to peak of the wave or trough to trough of the wave.

10. The peak of the wave is the highest point and the trough is the lowest point. In general, the wavelength is the distance between any chosen point in the wave and the next time that same point occurs.

11. Period & Frequency Period – in a wave gives you the time it takes for the wave to move through one wavelength, or one cycle. Frequency – in a wave gives you number of wavelengths passing through a point, or the number of cycles per unit time.

12. Instead of the wave’s period, you can talk about the wave’s frequency, which tells you the number of cycles of the wave per second at a point. Since frequency, is just the inverse of the period Frequency = 1/period

13.  You only need to know one – period or frequency- to be able to figure out the value of the other. The frequency unit of cycles per second has another name: Hertz

14. SPEED  In a wave tells us how fast It travels in the medium.  Speed depends on the medium in which the wave is traveling. Sound travels slower in air than in water. Sounds travels slower in water than in wood.