Answer:
I would say the answer is the wave of 21.000Hz
Explanation:
Because it has more frequency, and as more frequency you add, the time or longer period also increases.
Let say the two train cars are of masses
and 
now if the speed of two cars are
and 
then we can say that the momentum of two cars before they collide is given by

here two cars are moving in opposite direction so we can say that the net momentum is subtraction of two cars momentum.
Now since in these two car motion there is no external force on them while they collide
So the momentum of two cars are always conserved.
hence we can say that the final momentum of two cars will be same after collision as it is before collision

Answer:
32.1 N Please Give Brainliest
Explanation:
force = mass x acceleration
Answer : (B) Prominence
Explanation :
A large, glittering and gaseous characteristic which is extending outward from the surface of the sun is called <em>Prominence</em>.
<em>Photosphere</em> is one of the layer of sun where the prominence are anchored and then they move into the corona of the sun.
<em>Corona</em> is a region in the surface of the sun which is the constituent of hot ionized gases (plasma).
The prominence consists of colder plasma and this prominence plasma is much more shining and denser as compared to coronal plasma.
Hence, the correct option is (B) Prominence.
The ions are able to carry electric current through a solution. Some liquids such as oil or alcohol do not form ions and do not conduct electricity. Vinegar is mostly water with a small amount of acetic acid in it. The acetic acid separates into ions on so that the solution conducts electricity. BRAINLIST ME PEASE