Answer:
D.vibrations that cause changes in air pressure
Explanation:
Sound is a type of wave.
A wave is a periodic disturbance/oscillation that trasmits energy without transmitting matter. There are two different types of waves:
- Transverse waves: in a transverse wave, the direction of the oscillation is perpendicular to the direction of motion of the wave. These waves are characterized by the presence of crests (points of maximum positive displacement) and troughs (points of maximum negative displacement). Examples of transverse wave are electromagnetic waves.
- Longitudinal waves: in a longitudinal wave, the direction of the oscillation is parallel to the direction of motion of the wave. These waves are characterized by the presence of compressions (regions where the density of particle is higher) and rarefactions (regions where the density of particle is lower). Examples of longitudinal waves are sound waves.
Sound waves, in particular, consist of vibrations of the particles in a medium - most commonly, air - that occur back and forth along the direction of motion of the wave. Because of these motion, the air will have areas of higher pressure (which correspond to the compressions), where the density of particles is higher, and areas of lower pressure (which correspond to the rarefactions), where density of particles is lower.
Answer:
Frequency, 
Explanation:
Visible red light has a wavelength of 680 nanometers (6.8 x 10⁻⁷ m). The speed of light is 3.0 x 10 ⁸ m / s. What is the frequency of visible red light?
It is given that,
Wavelength of a visible red light is, 
Speed of light is, 
We need to find the frequency of visible red light. It can be calculated using below relation.
So, the frequency of visible red light is 
.
Answer: c
Explanation:
C Air is a compound of two or more components that keep their own identifying properties, while water is composed of mixtures that combine to form a compound.
Answer: <u>In a divergent plate boundary</u>, seafloor spreading taking place. It leads to the formation of oceans as new materials are added here along the mid-oceanic ridge. There occur volcanism and shallow-focus earthquakes.
<u>In a convergent plate boundary</u>, two plates collide to form high mountain belts and also volcanic eruptions take place. There occur long chains of volcanic as well as island arcs, in association with deep-focus earthquakes.
<u>In a transform plate boundary</u>, two plates slide past each other, conserving the plates. Shallow-focus earthquakes are generated here.
The earth has experienced various geological processes, such as weathering and erosion of rocks, earthquakes, volcanic eruptions, mass extinction events, plate tectonic movements and many more. These continuous processes have configured the present shape of the earth's surface.
For example, the breaking up of the supercontinent Pangea divided into Laurasia and Gondwanaland and subsequently formed the present scenario. This separation of continents has taken place due to the convection current that generates in the mantle.
