What is seismograph for ?

Earthquakes generate sound waves inside the earth. Unlike a gas, the earth can experience both transverse (S) and longitudinal (P) sound waves. Typically the speed of S wave is about 4.0 km s^-1 and that of P wave is 8.0 km s^-1 A seismograph records Pand Swavesfrom an earthquake. The first Pwave arrives 4 min before the first S wave. Assuming the waves travel in straight line, at what distance does the earthquake occur ?

What is biogas? What are its components ? What is the calorific value of biogas?

What is electrophoresis ? What is its significance ?

What is Apomixis ? What is its importance ?

Name the scale on which the destructive energy of an earthquake is measured . An earthquake measures ^3 on this scale. Would it be recorded by a seismograph ? Is it likely to cause much damage ?

Name the scale on which the destructive energy of an earthquakes is measured. An earthquake measures 3 on this scale. Would it be recordedby a seismograph? Is it likely to cause much damage?