PreCalc HW
1)Earthquake A had a magnitude of 8.2 on the Richter scale. At the same time an earthquake B with magnitude 4.8 caused only minor damage. How many times more intense was earthquake A than earthquake B? (Round your answer to two decimal places.)
2)One historic earthquake had a magnitude of 8.9 on the Richter scale. How many times more intense was this than another historic earthquake that had a magnitude of 8.2? (Round your answer to the nearest whole number.)
3)The Northridge, California, earthquake of 1994 had a magnitude of 6.8 on the Richter scale. A year later, a 7.2-magnitude earthquake struck Kobe, Japan. How many times more intense was the Kobe earthquake than the Northridge earthquake? (Round your answer to one decimal place.)
4)The intensity of the sound of traffic at a busy intersection was measured at 4.0 × 10−4 W/m2. Find the decibel level. (Round your answer to the nearest whole number.)
5)The intensity of the sound from a certain leaf blower is measured at 31 × 10−2 W/m2. Find the decibel level. (Round your answer to the nearest integer.)
6)The decibel level of the sound of a subway train was measured at 103 dB. Find the intensity in watts per square meter (W/m2). (Give your answer in scientific notation, correct to one decimal place.)
