When a layer of cold air close to the ground is covered by a layer of warmer air, sound waves traveling upward may be bent, or refracted, by the difference in temperature and redirected toward the ground.
Answer:
"A pendulum swinging back and forth" is an example of harmonic motion
X = Xo cos ω t
Explains the back and forth motion of the pendulum
Answer:
V = 192 kV
Explanation:
Given that,
Charge, 
Distance, r = 0.3 m
We need to find the electric potential at a distance of 0.3 m from a point charge. The formula for electric potential is given by :

So, the required electric potential is 192 kV.