-A photon travels, on average, a particular distance, d, before being briefly absorbed and released by an atom, which scatters it in a new random direction.
-Given d and the speed of light, c, you can figure out the average time step and space step size (how often the photon “steps” and how far it “steps” each time).
-The size of the Sun is figured in terms of step size. Some surprisingly tricky math happens, involving “Brownian motion” and probabilities. Finally,
-The average time it would take to get to the surface of the Sun is found.
If the echo (the reflected sound) reaches your ear less than about
0.1 second after the original sound, your brain doesn't separate them,
and you're not aware of the echo even though it's there.
If the echo comes from, say, a wall, 0.1 second means you'd have to be
about 17 meters away from the wall. If you're closer than that, then the
echo reaches you in less than 0.1 second and you're not aware of it.
A. 30 meters . . .
No. You hear that echo easily
B. you're standing within range of both sounds . . .
No. You hear that echo easily, if you're at least 17 meters from the wall.
C. less than 0.1 second later . . .
That's it. The echo is there but your brain doesn't know it.
D. 21.5 meters
No. You hear that echo easily.
Answer;
A. orographic lifting
Explanation;
Orographic lifting is a process that takes place when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain.
This can be explained by; When air is blocked by mountains, it cannot go through these mountains, As it ascends or moves up the mountain, the air then cools as it rises and when it cools to its saturation point, the water vapor condenses and cloud forms.
These clouds formed are known as orographic clouds, that develop in response to the lifting forced by the topography the earth.
Answer:
The thrust is 
Explanation:
Given that,
Mass of gas, 
The rate at which the gas is expelling, 
We need to find the thrust produced by the gas.
We know that force is equal to the rate of change of momentum. So,
Also, p = mv
So,
So, the thrust is
