2. Is an invisible force that draws together some metals : iron and steel. This force is specially strong at each end of the magnet ( north and south)
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4. SOUND Vibration through air If you can´t hear any sounds in a vacuum
5. Resonance An object always tends to vibrate freely at the same rate this natural frequency. The vibration can be faster or slower by jogging it at particular intervals.
7. SOUND FREQUENCY The difference is the frequency of the sound waves. If a sound waves follow very rapidly one after another, they are high-frequency and make a high sound. If there are low-frequency there will be a low sound.
8. Echo Is the sound of your voice bouncing back from the walls. Echoes only bounce back clearly off smooth,hard surfaces, and in confined spaces.
9. MAGNETIC FIELD The area around the magnet in which its effects are felt. It gets gradually weaker farther away from the magnet.