Question

imagine if a needle hits our planet Earth with the speed of light

what will happen ?​

Answer 1

I never accepted this question on brainly, but its there. A really very nice and brain storming question.

Here we go,

According to the classical mechanics, nothing would happen even if the needle is moving with a speed if light. Because there is huge difference between the mass of earth(6×10^24 kg) and mass of needle( ~ 10^-3 kg), and also between the speed of earth and that if needle.

So, according to the conservation if momentum, there is no reaction between the two.

-----------But----------------

According the theory of relativity, if any objet moves with a speed of light, it's mass increases.

And hence it's momentum tends to infinity.

Because of this, it doesn’t matter what the mass or velocity of the object the particle at the speed of light is striking, since it has infinite momentum, the collision will result in a massive loss of kinetic energy.

And such a wave of kinetic energy, combined with the impact of the collision, will probably destroy our planet and all life on it.

Answer 2

Really I never thought about such question

U are really very sharp minded Mr. Sapiens :-)

So according to the question if a needle will hit the earth nothing will happen, not a single thing will get destroyed.

This is because the density,mass and weight of earth and needle have a difference of land and sky ( ज़मीन आसमान का अंतर) .

According to conservation of momentum if a object moving with speed of light hit a larger object,no reaction will happen unless the object which is moving with speed of light is nearly half weighted of that object which is the target.

In easy language we can say that both should have a difference of half.

And in case of needle, it is really very small and thus it will cause no harm to earth.

Also I think it will burn until it cross the earth's atmosphere (this is according to me not from any scientist :-| )

But if a truck full of needle will hit earth maybe some needle will struck to some people (very bad for them ) and they will be admitted to hospital.

Then u can cure them (lol)

I hope this will never happen otherwise it would be one dangerous attack on Earth !

I hope it helps you

best of luck for exams ^_^