Answer:
Nitrogen and oxygen are by far the most common; dry air is composed of about 78% nitrogen (N2) and about 21% oxygen (O2). Argon, carbon dioxide (CO2), and many other gases are also present in much lower amounts; each makes up less than 1% of the atmosphere's mixture of gases.
Answer:
Mechanical waves require a medium in order to transport their energy from one location to another.
Sound waves are incapable of traveling through a vacuum. Slinky waves, water waves, stadium waves, and jump rope waves are other examples of mechanical waves; each requires some medium in order to exist.
Answer:
the first one.
Explanation: I don't exactly but, I know the other three sounds more like repetition! Hope this helps
1 and A
2 and B
3 and D
4 and C
Answer:
The observer sees the space-probe 9.055m long.
Explanation:
Let 
be the length of the space-probe when measured at rest, and 
be its length as observed by an observer moving at velocity 
, then
Now, we know that 
and 
, and putting these into 
we get:
Thus, an observer moving at 0.95c observes the space-probe to be 9.055m long.
