Mechanical waves require matter to travel medium. If there is no substance or matter to travel through, mechanical waves cannot propagate.
Since space is mostly vacuum, there is no medium for waves to travel through: waves sent by the sun (electromagnetic waves) are not mechanical waves
Answer:
Magnets strongly attract materials which already themselves have magnetic domains. They do not significantly attract many metals like gold, aluminum, silver, and even some types of high-chromium stainless-steel, which lack such domains. In fact, pure gold is slightly repelled.
Explanation:
Answer:
The phase difference is 
Explanation:
From the question we are told that
The distance between the slits is
The distance to the screen is 
The wavelength is 
The distance of the wave from the central maximum is 
Generally the path difference of this waves is mathematically represented as

Here
is the angle between the the line connecting the mid-point of the slits with the screen and the line connecting the mid-point of the slits to the central maximum
This implies that

=> 
![\theta = tan ^{-1} [\frac{5*10^{-3}}{1}]](https://tex.z-dn.net/?f=%5Ctheta%20%3D%20tan%20%5E%7B-1%7D%20%5B%5Cfrac%7B5%2A10%5E%7B-3%7D%7D%7B1%7D%5D)

Substituting values into the formula for path difference
The phase difference is mathematically represented as

Substituting values

Converting to degree
the solution is subtracted by 360° in order to get the actual angle
The answer is C 300,000 kilometers per second
Answer:
because the mass of the apple is very less compared to the mass of earth. Due to less mass the apple cannot produce noticable acceleration in the earth but the earth which has more mass produces noticable acceleration in the apple. thus we can see apple falling on towards the earth but we cannot see earth moving towards the apple.