All forms of matter are comprised of atoms. Wind in itself is the movement of particles(air). Wind does not have particles since it is an action and not a form of matter.
Answer:
Yes
Explanation:
Yes it is called the refractive index denoted by n
n=sin<i/sin<r
Answer:
Relation between initial speed of bullet and height h is given as

Explanation:
As we know that system of block and bullet swings up to height h after collision
So we have

so we have

so speed of the block + bullet just after the impact is given by above equation
Now we also know that there is no force on the system of bullet + block in the direction of motion
So we can use momentum conservation

now we have

Answer:
louder sound.
Explanation:
The amplitude of a sound wave determines its loudness or volume. A larger amplitude means a louder sound