Question-
Which seismic waves are felt first at a seismic station
Answer-
Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion. They are the energy that travels through the earth and is recorded on seismographs.
There are several different kinds of seismic waves, and they all move in different ways. The two main types of waves are body waves and surface waves. Body waves can travel through the earth's inner layers, but surface waves can only move along the surface of the planet like ripples on water. Earthquakes radiate seismic energy as both body and surface waves.
BODY WAVES
Traveling through the interior of the earth, body waves arrive before the surface waves emitted by an earthquake. These waves are of a higher frequency than surface waves.
P WAVES
The first kind of body wave is the P wave or primary wave. This is the fastest kind of seismic wave, and, consequently, the first to 'arrive' at a seismic station. The P wave can move through solid rock and fluids, like water or the liquid layers of the earth. It pushes and pulls the rock it moves through just like sound waves push and pull the air. Have you ever heard a big clap of thunder and heard the windows rattle at the same time? The windows rattle because the sound waves were pushing and pulling on the window glass much like P waves push and pull on rock. Sometimes animals can hear the P waves of an earthquake. Dogs, for instance, commonly begin barking hysterically just before an earthquake 'hits' (or more specifically, before the surface waves arrive). Usually people can only feel the bump and rattle of these waves.
P waves are also known as compressional waves, because of the pushing and pulling they do. Subjected to a P wave, particles move in the same direction that the the wave is moving in, which is the direction that the energy is traveling in, and is sometimes called the 'direction of wave propagation'. Click here to see a P wave in action.
Answer:
is the movement of substances due to random thermal molecular motion. is the diffusion constant, representative values of which are found in [link]. Osmosis is the transport of water through a semipermeable membrane from a region of high concentration to a region of low concentration.
Explanation:
(a) Agree
It is probable that less sticklebacks will have pelvic spines in Bear Paw Lake, as it is a smaller region without as much competition. Predators may be much lower in such an environment, eliminating a need for such protection. In the ocean, however, there is much biodiversity and competition, so the fish need pelvic spines to protect themselves.
Answer:
Because those chemical reactions help the cell to dispose useless substance after they are used and synthetize substance they need or the body needs through them.
Explanation:
Hello.
In this case, since the overall processes inside the cell are constantly producing and getting rid of several substances such as nutrients, proteins, lipids and other, we can say that decomposition reactions serve as a mechanism that the cell uses in order to obtain energy or dispose a substance that is no longer important for it. Moreover, since the cell is the fundamental part wherein the most of the useful substances the body needs are synthetized, we can infer that synthesis reactions must occur in order to allow the body to perform lots of functions, for instance, proteins associated to the hair or nails growing are synthetized inside the cell via the protein synthesis mechanism.
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