– Raw product weight vs Earth weight

Question

Lets suppose the Earth weighs 100,000 lbs. (just follow along).

I want to build a car from raw materials. The car will weigh 4000 lbs.

Does the the weight of the Earth change at that point or do the materials of the car equal the final weight of the car?

Same with humans. A baby weighs 10lbs at birth but when grown is 250lbs.

I suppose my question is that is the Earth’s weight a set weight or does is fluxuate barring any meteors an space junk.

In: 1

Answer 1

So lets assume the Earth is an isolated system, no space debris fall onto it and no material leaves. In that case conservation of matter applies. So no matter when you take a look at Earth its mass will be the same.

But the Earth isn’t an isolated system. Space debris do end up increasing the mass and some stuff leaves like rockets we shoot into space. Or low density gases escaping from the top of the atmosphere like helium.