Weight of the planet??

Question

Does the weight of the planet (Earth) ever alter?????....... e.g if someone cuts down say 1000 huge trees & burns them or 2000 jetliners are in the air at any one time, does the weight of the planet then increase when they land again??

Answer 1

Cutting down trees and burning them will release ash and smoke, and that ash and smoke remain on the planet. So, doing that cutting and burning will change nothing at all.
Same with those airliners. Anything that stays in the atmosphere can still be considered part of the planet's mass. For the few things in orbit, well, they do contribute to the "system's mass" the same way the Moon does.
Now, about this changing mass thing. There is a slow leak of excited atoms in the upper atmosphere getting zapped by cosmic rays and getting just enough energy to be thrown in space, never to return.
But this more than balanced by the million of small meteorites that fall on earth every day.
So, basically, the mass of the Earth has a tendency to grow ever so slightly each year.
But it would take billions of years before a difference can be noted.

Answer 2

Wow, i had the same thought... I think the planet will be lighter now than before however this is not due to things being burnt because the item will be fundamentally made from elements, these elements cannot be destroyed but they can be changed into other chemicals, combined they would weigh the same (i.e. if a tree was burned the water would evaporate, and the matter would turn to carbon/other chemicals, if all the smoke and particles where collected during the burning it would be the same weight as an unburned tree). However humans have launched some of the earths resources into space, this is where the weight difference would become apparent. I am not an expert so this could be (and probably is) wrong. If 2000 jets were in the air then the planets gross weight would = planet - 2000(jets), if they were on the ground the weight of the planet would be what it was before they took off - fuel (as the fuel is now in the air as particles)

Answer 3

The Earth does have weight. There is a gravitational pull on the Earth all the time...the main pulls come from our Moon and the Sun. Thus, we have tides and the Earth has weight.

Why...because "weight" is nothing more or less than a gravitational force exerted on a mass. A major equation in determining weight is F = GMm/R^2; where G is a constant, M is the mass of one body (like the Sun), m is another mass (like the Earth), and R is the distance between the two bodies. F is the force between the two bodies due to gravity.

Since the Earth and Sun are not significantly moving away from each other, the net forces between them are zero. Otherwise, one would be accelerating from the other. Therefore, we must conclude that the force on the Sun (by Earth) is equal to the force on the Earth (by Sun), but in opposite directions; so they cancel each other out. That force on the Earth pulling toward the Sun is its weight.

As to whether the Earth's weight changes...sure it does, continually. The masses (M and m) in the equation change all the time. The Sun (M) loses close to 5 million tons of matter every second as protons form helium to make the heat and light it produces from fusion. And Earth (m) gets tens of thousands of tons of meteors and comets crashing to the surface each day. So the masses, and thus the weights, change continually...but not so you'd notice on the grand scale of things.

On the other hand, R, the distance between the two bodies changes significantly. R varies by about 1.7% between the Earth's closest approach to the Sun (perihelion) and its farthest (aphelion). As the force F varies by the square of the distance between the two bodies, Earth's weight (F) will be about 3.4%heavier when close in than when farthest away from the Sun.

Answer 4

Actually, the 'weight' of the planet is zero, just like it is for space shuttles and astronauts. The mass of the earth, however, does not change, regardless of what happens on it, except for the slight losses from sending space probes away.

Of course, that is more than compensated for by incoming meteorites.

Answer 5

You are getting mass and weight confused. Weight is the gravitation pull generated from the larger of two objects. Planets, moons, stars, and anything else in space are measured by their mass.

Mass is T= 2 \pi \sqrt { \frac{r^{3}} {GM}}[/tex]

Ahh heck, just use the links provided to get a look at the equation.

Answer 6

Probably, but the change in weight is minute. It would be like saying if you weigh yourself, the difference in dust particles on your skin would alter your weight.

Of course, the Earth is technically weightless, as it is in space.

Answer 7

The Earth has no weight. It has mass. And the mass changes.

Meteorites are hitting the Earth regularily, increasing it's mass. Atmosphere is "leaking" to the space decreasing it's mass.

Does it increase or decrease, is (another) interesting question.

Answer 8

No idea, but would imagine that this would be almost impossible to work out! Have you ever seen them try to weigh a seriously obese person? If they have that much difficulty with fat folk, then they would have no chance with the planet!

Answer 9

Not in any measurable way.