#5036 Daily Warm-Ups: Nonfiction Reading teacher Created Resources #5036 Daily Warm-Ups: Nonfiction Reading Warm-Up
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3 Rain #5036 Daily Warm-Ups: Nonfiction Reading 44 ©Teacher Created Resources Warm-Up Check Your Understanding / 4 Name ______________________________________________ 1. According to the passage, what is the highest safe decibel level for humans? a. 130 dB c. 110 dB b. 70 dB d. 200 dB 2. At what decibel level does noise become physically painful and create a danger of long-term injury? a. 10 dB c. 110 dB b. 140 dB d. 70 dB 3. Which of the following is the most dangerous exposure for humans? a. firecrackers c. air-raid siren b. jet plane takeoff d. rocket takeoff 4. How much more powerful is a decibel level of 140 dB than a level of 130 dB? a. 2 times c. 100 times b. 10 times d. There is no way to tell. The loudness of sounds in the environment is measured in units called decibels, or dB. At 0 dB, sound is not loud enough to be heard by humans. A falling leaf or feather would be rated at 0 dB. At 10 dB, the sound is so soft that you can barely hear it. A true whisper from a friend in the next seat would be a 10 on the scale. A louder whisper across a classroom would register at 30 or 40 dB. A normal conversation would be expressed at about 60 dB. A noisy classroom or cafeteria is in the 70 dB range. A jackhammer registers at about 80 dB. Every 10-degree increase in decibels is ten times as loud as the one before, so that 70 dB is 10 times as loud as 60 dB. Noise above 70 dB is harmful to hearing and dangerous to the ears. Noise above 140 dB causes physical pain to your body. It may cause long-term injury to your ears if you often listen to this level of noise. Firecrackers can be as loud as 100 dB, and loud rock concerts and power saws are 110 dB or higher. A jet takeoff reaches 120 dB on the scale, as does a car horn at close range. An air-raid siren hits 140 dB, and a rocket takes off at 150 dB. At 145 dB, human eyeballs vibrate back and forth, and vision blurs. At 152 dB, the body feels severe pain in the joints. Throat vibrations caused by the sound can make swallowing difficult. Vibrations at 154 dB will pop a balloon, and 200 dB may result in death. Scientifically Speaking Download 10.24 Kb. Do'stlaringiz bilan baham: |
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