Earth Definition and 1000 Threads

I created interpolative curvefits to the graph of Earth's density as a function of radius, shown here: (Image from Wikipedia) Earth is assumed to be a sphere of radius 6371 kilometers. The independent variable r is the geocentric distance as a fraction of the Earth's radius; i.e. the range of...

If you could only choose one to research which would it be and why? My priority would be Earth first then space based purely on personal interest. Of course I would like to see more about both.

Suppose that the radius of Earth is 6400 km. Then what will be the capacitance of the Earth in micro farade unit?

If Earth moves at 500,000 MPH then why don't satellites get left behind? The solar system is orbiting the galaxy's central black hole, so, if you push a satellite in 1 direction while it attracts to Earth it will orbit Earth but should be left behind big time still. Also, if we were to place...

We know that the dinosaur was wiped out by a big meteor. Imagine a bullet hitting a hard surface,the Impact from the bullet should have moved the surface backwards right? So imagen that the meteor represent the bullet hitting the Earth and with that kind of impact it should have moved the Earth...

Most Lightening Strikes!

How magnetism acts on earth?

If the sun suddenly disappeared, we wouldn't know it for about eight minutes because that's how long it would take the light to travel the distance between the sun and the earth. But I've often wondered; if the sun suddenly disappeared, would the Earth continue in its orbital path around the...

Homework Statement My book said: As the Earth is rotating about its axis, objects on the Earth's surface are performing circular motion. Therefore, objects on the Earth are accelerating and they need a centripetal force. The weight contributes a small portion to the centripetal force needed...

i connected one probe of digital mutimeter to the Earth terminal of domestic ac supply and held the other probe. it showed resistance of 1.8Mohm . but when i touched that end (one i'd held) to the floor. it displays 1( beyond 200Mohm ). why so ? shouldn't resistance be lesser?doesnt any current...

Homework Statement Hi, Infinitely far away from a mass-->gravitational potential is zero. As get closer-->becomes negative. At surface-->it is the smallest value of r, i.e. the radius of the mass, hence the most negative value for gravitational potential. But as you go below surface of Earth...

In the MinutePhysics video "How long is a day in the Sun?" it is said 24 hours on Earth is 86,400.0 seconds, but on the Sun 86,400.2 seconds would pass. However, if time passes slower with more massed objects, then wouldn't a twin on the Sun be younger than a twin on the Earth? If so, is the...

Dear Forum, I am filmmaker from Berlin and despite physics focus back in high school I am really bad at it. I am trying to get my head around some ideas I am working on and would kindly ask you for some tiny calculations. I hope this is OK and maybe even fun for someone here? So my questions...

Hi, I am studying transmission lines faults. There was a line that said In case of delta star transformer in transmission line, an Earth fault on star (grounded) side is seen as a line to line fault on delta side. There was no explanation. I tried to google solutions but couldn't find any...

1. The problem statement, all variables and given/known ddata a.) Assume that a 100W light bulb covers 30cm^2 of area, and covers the surface of the Earth (land and water) with such 100W bulbs. How would the total power output compare with the luminosity of the Sun? Note: L_sun = 10^26W and...

Homework Statement Find the force exerted on a particle on the Earth by the sun. Homework Equations F = - GMm/r2 r = distance between sun and particle M = mass of sun G = Gravitational constant m = ? The Attempt at a Solution Should I be using the other mass as that of the earth, or that of...

I was watching a show on one of the science channels a couple of nights ago and I think I heard that Jupiter's gravitational pull on the sun is around half a million miles (or could have been kilometers). Now, depending on Jupiter's position in relationship to Earths, at any time does it...

Trees, plants grow. people eat, animals eat. Their dungs in ground everyday. People die. Does it have effect on the Earth mass? On its orbit around the sun?

Here's what my prof says: "Define F_{mean} to be the mean force, F_close to be the force on the side of the Earth closer to the moon, and F_far to be the force on the side of the Earth furthest away from the moon. On the closer side the net force is F_close - F_mean > 0 On the further side the...

Hello good people! If i liftoff from the Earth in a helicopter and continually ascend slowly, at that moment i have beat gravity(i realize it is still hanging on to me, however the rotorforce/upforce is greater than it), therefore gravity should no longer hold me to the ballearth(because it has...

I understand that c is the "ultimate speed" and that it is a result of the fundamental constant, the permeability of free space. But if this is a constant only to a "stationary" frame of reference, how can we accurately measure it from Earth? Since Earth is moving relative to a supposed "fixed"...

I was wondering how they managed to know the internal structure of Earth and it's composition while there is lava and it's very hot such that no any instruments can get there...seriously I am confused

Homework Statement A pendulum clock is adjusted so that it keeps excellent time on the ground. The clock is brought to a mine of depth h below the ground and then raised a height h above the ground to see the differences. In which case is the error larger? Homework Equations T = 2π √(L/g) L =...

Can anyone in the cosmology community direct me to hard research data that specifically demonstrates: there is no detectable redshift difference in stars that are the same distance from the Earth but in all different directions. This is of course related to 'does the universe have a preferred...

Hi. In a normal power plug, neutral is on the same potential as the Earth and therefore, in theory, safe to touch. Line carries the full voltage difference and is dangerous if the body provides a conducting connection to the earth, since this closes the circuit to neutral. Isolation...

Homework Statement An object of mass ##m## moves in a smooth, straight tunnel dug between two points on the Earth’s surface. Show that the object moves with simple harmonic motion, ##a = - ω^2 x##. Find the period of this motion. You can assume that the Earth’s density is uniform. Homework...

Homework Statement 1) the right bank of rivers and streams is usually eroded their left side in the northern hemisphere and the reverse is observed in the southern hemisphere, why 2) asymmetrical wear on the rails, right in the northern hemisphere and to the left in the southern hemisphere...

http://phys.org/news/2016-10-deadly-nearby-gamma-ray.html How deadly would a nearby gamma ray burst be? The original paper in Astrobiology is locked, but this summary is pretty complete. "A burst at the South Pole fits in with theories of the Ordovician extinction because the measured...

I always wondered why they say water and photons created the first microbes which later evolved and produced oxygen which filled our oceans and atmosphere. So how could have water existed without oxygen? I tried to look up and came up with different explanations, but it doesn't make sense.

Let's say a single human exits the atmosphere? Why doesn't he orbit the Earth like the moon does? Why does he drift in space instead?

I've been tinkering with a few diagrams in an attempt to illustrate the motion of the solar system in its journey around the Milky Way. I also wanted portray how the celestial, ecliptic and galactic coordinate systems are related to each other in a single picture. Note: in the Celestial, or...

Homework Statement When a cart travel to the left at v=-10m/s, the angle of rain come towards it is 50o from normal. When the cart travel to the right at v=10m/s, the angle of rain water come is perpendicular to it. What is the angle of rain come to the earth? Homework Equations relative...

hi, I got inspiration from alien, Prometheus, and knight of Sidonia(Japanimation) in these SIFI contents, I ve seen artificial things that stand quite long time. when it comes to man made structure, material, or method, I wonder is there any chance to survive million year on earth? structure...

In relation to two objects with a gravitational field on them (i.e. a planet and its moon), would there be two pairs of partner forces (the force of gravity exerted from each object and the resulting partner force from each force of gravity)? For example with the Earth and moon: 1. Force of...

How does this work exactly? I can understand depending on frame of reference but I read that Einstein stated there is a right way to think about that based on inertial and non-inertial frame of references.

I always thought the force of gravity between two objects on Earth wasn't significant enough for there to be an apparent acceleration between the objects. But I tried calculating the force of gravity for massive objects, like the Great Pyramid of Giza, the force seems to be quite significant...

I want to build a model of how the ecliptic interacts with the horizon. The horizon appears to be a flat circle, so I thought I'd use a CD sized shape for that. What shape would I use for the ecliptic, and how large relative to the CD? I would like it to be as close as possible to the my...

Ok, I am sure similar questions have been asked but here it goes. You start digging a hole with the intention of digging straight through the planet. Your hole will be straight but will only go through the mantle, missing the core and outer core, so you have avoided the weightlessness of the...

why Earth moves around sun forever and ever and ever. My attempt for answer: Earth wants to move in straight Line forever and ever and ever(as there is no ext. Force)but due to massive sun space get bends(according to GR) and moving Earth starts moves in circle(or not perfect circle) , as it...

Imagine a hole drilled through the Earth from which all air has been removed thus creating a vacuum. Let a cluster of test particles in the shape of a sphere be dropped into this hole. The volume of the balls should start to decrease. However, in his article "The Meaning of Einstein's Equation"...

Homework Statement Homework Equations ε= r_max - r_min / r_max + r_min = r*v2 / gRE The Attempt at a Solution I first find that 1 revolution is 2π rad , the angular velocity ω = 2π rad / 24h = π/43200 rad /s so v = rω where r is the unknown ε = 0 (circular orbit) r*(rω)2 / g RE = 0Correct...

Homework Statement A cannon that is capable of firing a shell at speed V_0 is mounted on a vertical tower of height h that overlooks a level plain below. (a) Show that the elevation angle \alpha at which the cannon must be set to achieve maximum range is given by the expression...

theoretically if you were in the center of the earth, would you age slower or faster from time dilation? this question is asked here as well: https://www.quora.com/Can-someone-calculate-the-time-dilation-if-you-were-in-a-5000-km-deep-cave-How-much-longer-would-my-life-be this is a wrong...

How (more accurately) Earth is a non inertial frame? A frame of reference(FOR) will be a non-inertial when a=0 ⇔ F =0 Suppose a book on a table is our object and Earth as a Frame of reference, generally we take accelaration of book w.r.t Earth as 0 but more accurately it is not 0(because...

Homework Statement If the radius of of the Earth were to shrink by one percent, its mass remains the same,g would decrease by nearly...% Homework Equations g=GM/ R^2 The Attempt at a Solution Well, I took g1= GM/R^2 And gravity after shrinking as g2= GM/(R-(R/100))^2 Then I did g1-g2 and I...

Homework Statement A ship sets sail from Rotterdam, The Netherlands, heading due north at 7.00 m/s relative to the water. The local ocean current is 1.50 m/s in a direction 40.0º north of east. What is the velocity of the ship relative to the Earth? Homework Equations Vr=Vs-Vc r=relative...

If the Earth were hollow and we only had the shell could a black hole at the center take the place of all the mass and provide us with gravity to keep us from floating away?

This is a question that has been bothering me, but I can't find an answer anywhere: If I were to hollow out Earth so that the crust was the only mass, and Earth was to keep it's shape, how would this affect the outside gravity?

Homework Statement A nova is the sudden, brief brightening of a star. Suppose Earth astronomers see two novas occur simultaneously, one in the constellation Lyra. Both nova are the same distance from Earth, ## 2.5 \times 10^3 [cy]##, and are in exactly opposite direction from Earth. Observers...

Homework Statement Homework EquationsThe Attempt at a Solution I think if the astronaut can somehow throw it behind himself, against the direction of orbital motion ( 180° opposite ) such that the total orbital velocity of the nut is canceled , it should fall straight down . But this is...