Interactive practice questions
The histogram below shows the area (in km2) for $12$12 countries, plotted using a log scale.
How many countries have an area of between $10000$10000 km2 and $100000$100000 km2?
The Richter Scale is a logarithmic scale used to measure the magnitude of an earthquake or tremor. An earthquake that registers $4.0$4.0 on the Richter scale is $10$10 times stronger than an earthquake that measures $3.0$3.0.
How many times stronger is a quake of $7.6$7.6 than one of $5.2$5.2?
Give your answer to the nearest whole number.
The decibel scale, used to record the loudness of sound, is a logarithmic scale. The lowest audible sound, with intensity $10^{-12}$10−12 watts/m2 is assigned the value of $0$0. A sound that is $10$10 times louder than this is assigned a decibel value of $10$10. A sound $100$100 ($10^2$102) times louder is assigned a decibel value of $20$20, and so on. In general, an increase of $10$10 decibels corresponds to an increase in magnitude of $10$10.