Answer:
Waves are caused by wind, or are created by the friction between wind and surface water
Explanation:
Answer:

Explanation:
The magnitude of the electrostatic force between two charged objects is

where
k is the Coulomb's constant
q1 and q2 are the two charges
r is the separation between the two charges
The force is attractive if the charges have opposite sign and repulsive if the charges have same sign.
In this problem, we have:
is the distance between the charges
since the charges are identical
is the force between the charges
Re-arranging the equation and solving for q, we find the charge on each drop:

<u>Answers
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1) B. longitudinal.
2) B. air is cooler than the ground.
<u>Explanation
</u>
Q1
There are two categories of a wave. That is transverse and longitudinal waves. Transverse waves forms crests and troughs while longitudinal forms compressions and rarefaction as they travel. Rarefactions are regions where the wavelengths are longer than other regions.
Q2
As the ray of light moves from an optically less dense to a more dense region it bends towards the normal.
If the sound is bending away from the earth's surface, then the ground must be warmer than the air. As the sound travels it moves from optically dense medium to a less dense medium. For this reason it bends away from the normal. This can only happen when, B. air is cooler than the ground.
The first one is D hunted with stone-tipped spears
The second one is A
Hope this helps