Question

An earthquake generates three types of waves: surface waves (L waves), which are the slowest and weakest; cutting waves (S waves), which are transverse waves and carry most of the energies, and pressure waves (P waves), which are longitudinal waves that move faster. The speed of the P waves is approximately 7.0 km / s, and that of the S waves is approximately 4.0 km-7s. It seems that animals feel the waves P. If a dog feels the arrival of P waves and begins to bark 30.0 seconds before the earthquake is felt by humans, what is the approximate distance of the dog from the epicenter of the earthquake?

a	280 km
b	80 km
c	221 km
d	3.45km

Answer 1

***************************************************************************************************
Check the answer and let me know immediately if you find something wrong... I will rectify the mistakes asap if any