Hey aspirant,

According to Kepler's Law of Planetary motion, T^2 is directly proportional to R^3, where T is time period and R radius.

Therefore the ration of the time period is given as :- (T1/T2)^2 =(1/4)^3 = 1/64

So, T1/T2 = 1/8.

Hope this helps,

All the best!

Hello student,

I hope you are doing well.

Seismic tomography resolves anomalies interpreted as oceanic lithosphere subducted deep into Earth’s lower mantle. However, the fate of the compositionally distinct oceanic crust that is part of the lithosphere is poorly constrained but provides important constraints on mixing processes and the recycling process in the deep Earth. When an earthquake occurs the seismic waves (P and S waves) spread out in all directions through the Earth's interior. Seismic stations located at increasing distances from the earthquake epicenter will record seismic waves that have traveled through increasing depths in the Earth.

Seismic velocities depend on the material properties such as composition, mineral phase and packing structure, temperature, and pressure of the media through which seismic waves pass. Seismic waves travel more quickly through denser materials and therefore generally travel more quickly with depth. Anomalously hot areas slow down seismic waves. Seismic waves move more slowly through a liquid than a solid. Molten areas within the Earth slow down P waves and stop S waves because their shearing motion cannot be transmitted through a liquid. Partially molten areas may slow down the P waves and attenuate or weaken S waves.

When seismic waves pass between geologic layers with contrasting seismic velocities (when any wave passes through media with distinctly differing velocities) reflections, refraction (bending), and the production of new wave phases (e.g., an S wave produced from a P wave) often result. Sudden jumps in seismic velocities across a boundary are known as seismic discontinuities.

THE CRUST:

Seismic stations within about 200 km of a continental earthquake (or other seismic disturbance such as a dynamite blast) report travel times that increase in a regular fashion with distance from the source. But beyond 200 km the seismic waves arrive sooner than expected, forming a break in the travel time vs. distance curve. Mohorovicic (1909) interpreted this to mean that the seismic waves recorded beyond 200 km from the earthquake source had passed through a lower layer with significantly higher seismic velocity. This seismic discontinuity is now know as the Moho (much easier than "Mohorovicic seismic discontinuity") It is the boundary between the felsic/mafic crust with seismic velocity around 6 km/sec and the denser ultramafic mantle with seismic velocity around 8 km/sec.

THE MANTLE:

Seismic velocities tend to gradually increase with depth in the mantle due to the increasing pressure, and therefore density, with depth. However, seismic waves recorded at distances corresponding to depths of around 100 km to 250 km arrive later than expected indicating a zone of low seismic wave velocity. Furthermore, while both the P and S waves travel more slowly, the S waves are attenuated or weakened. This is interpreted to be a zone that is partially molten, probably one percent or less (i.e., greater than 99 percent solid).  Alternatively, it may simply represent a zone where the mantle is very close to its melting point for that depth and pressure that it is very "soft."  Then this represents a zone of weakness in the upper mantle. This zone is called the asthenosphere or "weak sphere."

I hope you find it useful.

Hi Yurom!

Seismic Waves occurs when earthquake is formed and spreads in all directions through the Earth's Interior which are recorded by the Seismic Stations.

Seismic Velocities depend on the factors of Material Properties such as composition, mineral phase, structure, temperature and pressure through which the Seismic Waves pass.

Below are the layers of the Earth's Interior:

• First Layer is the Crust. It is less dense.
• Second Layer is the Mantle which is also known as the Low Velocity Zone.
• Then comes the Core which is divided as Outer Core and Interior Core.

Hope this is helpful!

All the best!

When an earthquake occurs the seismic waves (P and S waves) spread out in all directions through the Earth's interior.

Seismic velocities depend on the material properties such as composition, mineral phase and packing structure, temperature, and pressure of the media through which seismic waves pass. Seismic waves travel more quickly through denser materials and therefore generally travel more quickly with depth. Anomalously hot areas slow down seismic waves. Seismic waves move more slowly through a liquid than a solid. Molten areas within the Earth slow down P waves and stop S waves because their shearing motion cannot be transmitted through a liquid. Partially molten areas may slow down the P waves and attenuate or weaken S waves.

When seismic waves pass between geologic layers with contrasting seismic velocities (when any wave passes through media with distinctly differing velocities) reflections, refraction (bending), and the production of new wave phases (e.g., an S wave produced from a P wave) often result. Sudden jumps in seismic velocities across a boundary are known as seismic discontinuities . SESIMIC (http://www.columbia.edu/~vjd1/earth_int.htm)

Hello,

Your question is not very clear. If you are asking what is the radius of the earth then Its equatorial radius is 6378 km , but its polar radius is 6357 km. I hope this clears your doubt, If not please ask the question giving more details and we will try to help to the best of our know;edge

Good Luck

Hello Vennapusa charan kumar reddy,

Well, at the terminal velocity, its velocity will not change, hence its momentum will also not change and therefore rate of change of momentum is 0 or the accelaration will be 0 (since accelaration = rate of change of momentum ), so: At the terminal velocity,

Fnet=mg−FD=ma=0.(where FD is the drift force due to air resistance, say FD = 1/2CρAv^2 )(where C is constant, ρ is the density of air, A is the surface area of the body, V is the velocity of body and in this case V = Vt or terminal velocity )

Thus,

mg=FD.mg=FD.

Using the equation for drag force, we have

mg=1/2CρAv^2

Solving for the velocity, we obtain

vt=√2mgρCA.

for more details you can refer to ( Terminal Velocity (https://courses.lumenlearning.com/suny-osuniversityphysics/chapter/6-4-drag-force-and-terminal-speed/) )

Hope this helps, and feel free to ask any further query...

Hi Candidate,

A geostationary satellite moves from West to East and has a time period of Oscillation about it's axis which is equal to 24 hours same as the Earth. It pretends to be stationary with respect to the Earth but if we talk about the Angular Speeds of both the Earth and the Geostationary satellite, they are different.

Hence, the correct option is B.

Hope that this answer helps you.

Hello student.

Hope you are doing well.

As per the data collected, it is said that earlier there were two moons orbiting around the earth before it collided with present day moon.

The lunar havoc would have been increased causing massive tsunami's, earthquakes, volcanic eruptions. But it would have been normal after some time giving some chance for the life tk exist on earth.

For more information, you can read the article present at this link:

https://www.google.com/amp/s/phys.org/news/2011-12-earth-moons.amp

Hope this will help you and it solves your query.

Have a great day!

Good luck!!

Hi Sakshi,

Terrestrial part of Earth is called the Lithosphere. A lithosphere refers to the rigid, outermost shell of a terrestrial planet or natural satellite, which is defined by its rigid mechanical properties. Earth's lithosphere includes the crust and the uppermost mantle, which makes up the rigid and hard outer layer of the Earth. The lithosphere is subdivided into tectonic plates.There are two types of lithosphere, oceanic lithosphere, which is associated with oceanic crust and exists in the ocean basins. The second one is continental lithosphere, which is associated with continental crust or the land area on Earth.

Hope it is helpful.

Hello,

Hope you are doing well.

As per your question, if we consider solid angle as theta then it is normally defined as theta equals to diameter upon distance . So it would be like 3.47 *10³ divide by 3.84*108 so this would give result as 9.0*10-.

So the solid angle subtended by the moon at any point of earth is 9.0 *10-.

So hope this information helps you out. Thank you.