Someone please help me with number 4

Write an explicit formula that represents the sequence defined by the following recursive formula:

Find the average speed of a rabbit that runs a distance of 22 m in a time of 1.8 s .

The magnitude, m, of an earthquake is defined to be m=log l/s, where i is the intensity of the earthquake (measured by the amplitude of the seismograph wave) and s is the intensity of a “standard” earthquake, which is barely detectable. what is the magnitude of an earthquake that is 1,000 times more intense than a standard earthquake? use a calculator. round your answer to the nearest tenth.