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Science_Lab_Yellow / Lesson 4: How Do Waves move

 How Do Waves Move What will we be learning today? In this lesson, we are going to learn how waves move.

 How Do Waves Move? All waves carry energy from place to place. The way a wave carries energy depends on the kind of wave motion.

 Remember that sound waves are produced by vibrations. As a string or bar or some other object vibrates, it causes molecules of gas in the air to move back and forth. The energy of the vibration is carried through the air to your ear. In a similar way, sound waves travel through solids, liquids, and gases.

The wave in the spring below moves from left to right. Notice that the particles of matter also vibrate back and forth along the same direction-from left to right.

 By vibrating one end of a spring toy in and out, you can see waves travel much as sound waves do.

 Without particles vibrating back and forth in the direction the sound is traveling, the energy of the sound vibration could not travel. Sound waves cannot travel in a vacuum, a space where there is no matter.

If you toss a pebble into a quiet pond, you can see waves travel across the surface. How does a particle of matter move in the water as the wave moves past it from left to right? Each particle moves in a circle. So does the ball floating on the water.

 As the wave moves from left to right, how do the water and the ball move?

The waves shown below also move from left to right. How does a particle in the string or the spring move when a wave passes through it? It does not move back and forth as in a sound wave. It does not move in a circle as in a water wave. It moves up and down.