An earthquake generates three kinds of waves: surface waves (L waves), which are the slowest and weakest; shear (S) waves, which are transverse waves and carry most of the energy; and pressure (P) waves, which are longitudinal waves and travel the fastest. The speed of P waves is approximately 7.0 km/s, and that of S waves is about 4.0 km/s. Animals seem to feel the P waves. If a dog senses the arrival of P waves and starts barking 39.5 s before an earthquake is felt by humans, approximately how far is the dog from the earthquake’s epicenter? pleaaseeee !!!

Question

An earthquake generates three kinds of waves: surface waves (L waves), which are the slowest and weakest; shear (S) waves, which are transverse waves and carry most of the energy; and pressure (P) waves, which are longitudinal waves and travel the fastest. The speed of P waves is approximately 7.0 km/s, and that of S waves is about 4.0 km/s. Animals seem to feel the P waves. If a dog senses the arrival of P waves and starts barking 39.5 s before an earthquake is felt by humans, approximately how far is the dog from the earthquake’s epicenter?  pleaaseeee !!!

drwls · Answer

Shear (S) waves arrive next, after P.
For each kilometer distance from epicenter, there is a delay of 1/4 - 1/7 = 0.107 seconds between those two waves.

A 39.5 second delay means the distance is 369 miles.

maria · Answer

An earthquake generates three kinds of waves: surface waves (L waves), which are the slowest and weakest; shear (S) waves, which are transverse waves and carry most of the energy; and pressure (P) waves, which are longitudinal waves and travel the fastest. The speed of P waves is approximately 7.0 km/s, and that of S waves is about 4.0 km/s. Animals seem to feel the P waves. If a dog senses the arrival of P waves and starts barking 39.5 s before an earthquake is felt by humans, approximately how far is the dog from the earthquake’s epicenter? pleaaseeee !!! ('drwls' 369 miles is wrong answer :( ! can you calculate with meter pleasee )

bobpursley · Answer

distancein km= 1km/.107*39.5s=369km

maria · Answer

An earthquake generates three kinds of waves: surface waves (L waves), which are the slowest and weakest; shear (S) waves, which are transverse waves and carry most of the energy; and pressure (P) waves, which are longitudinal waves and travel the fastest. The speed of P waves is approximately 7.0 km/s, and that of S waves is about 4.0 km/s. Animals seem to feel the P waves. If a dog senses the arrival of P waves and starts barking 23.3 s before an earthquake is felt by humans, approximately how far is the dog from the earthquake’s epicenter?