Answer:
Volcanic activity is widespread over the earth, but tends to be concentrated in specific locations. Volcanoes are most likely to occur along the margins of tectonic plates, especially in subduction zones where oceanic plates dive under continental plates. As the oceanic plate subducts beneath the surface, intense heat and pressure melts the rock. Molten rock material, magma, can then ooze its way toward the surface where it accumulates at the surface to create a volcano. Volcanic activity can be found along the Mid-ocean ridge system as well. Here, oceanic plates are diverging and magma spreads across the ocean floor, ultimately being exposed at the surface. Crustal spreading long the ridge is partly responsible for the volcanic activity of Iceland. It is also thought that a "hot spot" lies beneath the island that contributes to volcanism.
Answer:
i guess 0.8 miles away
Explanation:
mathematically:-
speed is given in question
Time is given
and we have to find distance
simply by using speed formula (s) = d/t
we get answer
To solve this problem we will apply the concepts of linear mass density, and the expression of the wavelength with which we can find the frequency of the string. With these values it will be possible to find the voltage value. Later we will apply concepts related to harmonic waves in order to find the fundamental frequency.
The linear mass density is given as,
The expression for the wavelength of the standing wave for the second overtone is
Replacing we have
The frequency of the sound wave is
Now the velocity of the wave would be
The expression that relates the velocity of the wave, tension on the string and linear mass density is
The tension in the string is 547N
PART B) The relation between the fundamental frequency and the 
harmonic frequency is
Overtone is the resonant frequency above the fundamental frequency. The second overtone is the second resonant frequency after the fundamental frequency. Therefore
Then,
Rearranging to find the fundamental frequency
The electrostatic force is directly proportional to the product of the charges, by Coulomb's law.
F α Qq
If the charges are now half the initial charges:
<span>F α (1/2)Q *(1/2)q
</span>
F α (1/4)Q<span>q
The new force when the charges are each halved is (1/4) the first initial force experienced at full charge.</span>
