Some of the reasons that can cause can earthquake are volcanic eruptions, the grinding of tectonic plates beneath the earth's crust and violent explosions which can be artificially induced as well. No matter what the reason is, earthquakes affect the environment and earth's surface. Noticeable cracks have formed on the earth's surface after earthquakes. If the tremors are violent, it can result in the destruction of landscapes. The mountains become prone to land sliding. the glacier's become a threat because of fear of avalanches. tsunamis which are earthquakes in the ocean bed can cause heavy flooding which causes water to cross all boundaries and shores and flood entire cities. Earthquakes caused by volcanoes can result in the spewing of so much lava that it may spill everywhere and cool changing the surface of the earth geologically as well as the ash causing aerial pollution.
A pendulum is not a wave.
-- A pendulum doesn't have a 'wavelength'.
-- There's no way to define how many of its "waves" pass a point
every second.
-- Whatever you say is the speed of the pendulum, that speed
can only be true at one or two points in the pendulum's swing,
and it's different everywhere else in the swing.
-- The frequency of a pendulum depends only on the length
of the string from which it hangs.
If you take the given information and try to apply wave motion to it:
Wave speed = (wavelength) x (frequency)
Frequency = (speed) / (wavelength) ,
you would end up with
Frequency = (30 meter/sec) / (0.35 meter) = 85.7 Hz
Have you ever seen anything that could be described as
a pendulum, swinging or even wiggling back and forth
85 times every second ? ! ? That's pretty absurd.
This math is not applicable to the pendulum.
Any charged object can<span> exert the force upon other objects ... i think tell me if im right</span>
Iron is a magnetic metal, and it is essential to the Earth's magnetic field!
Essentially it "records" (stores the information, maintains) the direction and orientation of the magnetic field.
Among others, the magnetic field protects the Earth from dangerous cosmic rays.