No traces of a meteorite were found, it many scientists concluded that the culprit was a comet. Comets, which are essentially muddy ice balls, could cause such a devastation and leave no trace.
But now, 105 years later, scientists have revealed that the Tunguska devastation was indeed caused by a meteorite. A group of Ukrainian, German, and American scientists have identified its microscopic remains. Why it took them so many years makes for a fascinating tale about the limits of science and how we are pushing them.
Answer:

Explanation:
From the question we are told that:
Frictional force 
Coefficient of kinetic friction 
Generally the equation for Normal for is mathematically given by

Therefore


Answer:
The modern instruments or we can say the different levels of telescopes are used to explore and study the distant galaxies. i.e the Hubble telescope is out there providing the data regarding the different properties of the celestial entities which in other case is not visible to the human naked eye.
Explanation:
- Scientists and research workers are in constant search for more answers as they explore the universe and implement the laws of physics on the celestial entities. But, most of the objects inside the universe are not visible to human naked eye, as they are far from sight and thus more advanced form of instruments like the x-ray, optical, and light telescopes are used to determine the different properties of the celestial entities inside the universe.
- As, these telescopes includes the most recent "Hubble telescope", which is out there inside the space to explore the universe and more over the galaxies by subjecting them with x-rays and then provide us with a very rough but valid results to study the distant galaxies.
That's a molecule of the substance. You can break the molecule down further, into the atoms that make it up, but those don't have the properties of the original 'compound'.
Here's an example:
-- Sodium is a soft, slippery metal, that explodes when water touches it.
-- Chlorine is a poisonous green gas.
When an atom of Sodium and an atom of Chlorine combine, they make one molecule of a substance called "Sodium Chloride". That's SALT ! It isn't green, it isn't a gas, it isn't poisonous, it isn't soft and slippery, and it doesn't explode when water touches it.
Answer:
Its traveling in the +x direction
Explanation:
The E-field is in the +y-direction, and the B-field is in the +z-direction, so it must be moving along the +x-direction, since the E-field, B-field and the direction of moving are all at right angles to each other.