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# Using a Graph of Sound Strength

The intensity or sound (its relative loudness) decreases as distance from the source increases. It changes as the inverse of the distance squared( 1 / r2 ). If you double your distance from the source the intensity is 1/4 its previous strength. It may not sound exactly ¼ as strong because of the way your ears adjust for sound intensity. The graph below shows sound intensity versus distance from a sound source. Use the graph to answer the following questions. Be as accurate as you can ! 1. What is the relative intensity of the sound when you are 0.4 meter away ? __________
2. What is the relative intensity of the sound when you are 0.5 meter away ? __________
3. What is the relative intensity of the sound when you are 1 meter away ? __________
4. What is the relative intensity of the sound when you are 2 meters away ? __________
5. How close to the sound source are you if the relative intensity is 10 ? __________
6. How close to the sound source are you if the relative intensity is 7 ? __________
7. How close to the sound source are you if the relative intensity is 5 ? __________
8. How close to the sound source are you if the relative intensity is 2 ? __________
9. On the back, use the graph to explain how distance can be used to protect your hearing from damage due to loud sounds (like head phones). Be specific - imagine what the sound intensity must be when you are getting within one centimeter of your ear!