The correct answer to the question is - A). Light waves can travel in a vacuum and travel at a constant speed even if the light source is moving.
EXPLANATION:
Before going to answer this question, first we have to understand the fundamental postulate of quantum mechanics.
As per the fundamental postulate of quantum mechanics, the speed of light is always constant irrespective of the nature of frame of reference i.e speed of light is same both in inertial and non-inertial frame of reference. It is independent of the velocity of source also.
Again we know that light is an electromagnetic wave. Hence, it won't require any medium for its propagation. It can travel in space or vacuum also.
Hence, the correct option out of four options is that light waves can travel in a vacuum and travel at a constant speed even if the light source is moving.
If the north and south pole crosses, radiations can enter Earth's atmosphere easily, continents will lurch in one directions causing natural calamities and species extinction.
<u>Explanation:</u>
- The North and South pole forms the Earth's magnetic field which protects us from harmful radiation entering the atmosphere. If these poles get flipped, a global cataclysm may occur.
- The continents will move to one direction causing massive earthquakes, rapid change of weather and climate and results in species extinction.
- Over the past 150 years, the magnetic poles are casually moving but now it is moving very fast which may result in a flip of the magnetic poles.
- Earth's magnetic field is what shields us from harmful space radiation which can damage cells, causing cancer, and fry electronic circuits and electrical grids. With a weaker field in place, This will disrupt the internal compass and many navigations may get interrupted
Answer:
Twice
Step-by-Step Explanation:
Time between 7:00 PM and 1:00 AM: 6 hours
Distance: 4818km
Since the distance is 4818km, and the time is 6 hours, you divide 4818 by 6.
803.0000015999 km/h.
The average speed is 803 km/h
Which considering the ideal case scenario if the plane starts at 0 reaches the speed of 803 and the end reduces its speed from 803 to 0. This means we have come across the value of 800 at least twice. Hence, the plane was travelling at a speed of 800 km/h at least 2 times.