Answer:
a. 
b. 
Explanation:
Given:



The runner force average to find given the equations
a.




b.
Work done by the system by this force so





The result of a wave generator traveling faster than the speed of a wave is called as a boom. If the wave is a sound wave, it is called a sonic boom. However, if the wave is light, it is called as a luminal boom. Luminal bloom happens in some industries and is commonly called as the Cherenkov radiation.
Answer:
350 miles
Explanation:
When the car starts 2 hours later, the train would have a head start of
50 * 2 = 100 miles
The speed of the car relative to the train is
70 - 50 = 20 mi/hr
For the car to catch up with the train, it must cover the 100 miles difference at the rate of 20mi/hr. So the time it would need to cover this difference is
100 / 20 = 5 hours
After 5 hours, the car would have traveled a distance of
5 * 70 = 350 miles which is also the distance from the station to where the car catches up
Atmospheric refraction is the deviation of light or other electromagnetic wave from a straight line as it passes through the atmosphere due to the variation in air density as a function of height. ... Refraction not only affects visible light rays, but all electromagnetic radiation, although in varying degrees.
So in short, the answer is D.
(My answer got deleted because it didnt explain which is dumb)