The girl may hear from the front
Tropospheric ozone is produced through interaction of heat and UV light, with nitrogen oxides and carbon containing compounds.
Option: D
Explanation:
In earth's atmosphere there are total five layers: Troposphere, Stratosphere, Mesosphere, Ionosphere and Exosphere. Stratosphere is known as Ozonosphere where ozone layer is present with the key constituent ozone. Ozone layer is very important as it protects whole environment from harmful UV rays coming from space.
Tropospheric ozone is produced through the interaction of heat and UV light with nitrogen oxides and carbon containing compounds. Ozone plays a dual role in environment when it is in lower surface area it is a harmful gas and when it is in atmospheric layer it is a life saving layer.
Well, there you have a very important principle wrapped up in that question.
There's actually no such thing as a real, actual amount of potential energy.
There's only potential <em><u>relative to some place</u></em>. It's the work you have to do
to lift the object from that reference place to wherever it is now. It's also
the kinetic energy the object would have if it fell down to the reference place
from where it is now.
Here's the formula for potential energy: PE = (mass) x (gravity) x (<em><u>height</u></em><u>)</u> .
So naturally, when you use that formula, you need to decide "height above what ?"
If you're reading a book while you're flying in a passenger jet, the book's PE is
(M x G x 0 meters) relative to your lap, (M x G x 1 meter) relative to the floor of the
plane, (M x G x 10,000 meters) relative to the ground, and maybe (M x G x 25,000 meters)
relative to the bottom of the ocean.
Let's say that gravity is 9.8 m/s² .
Then a 4kg block sitting on the floor has (39.2 x 0 meters) PE relative to the floor
it's sitting on, also (39.2 x 3 meters) relative to the floor that's one floor downstairs,
also (39.2 x 30 meters) relative to 10 floors downstairs, and if it's on the top floor of
the Amoco/Aon Center in Chicago, maybe (39.2 x 345 meters) relative to the floor
in the coffee shop that's off the lobby on the ground floor.
To develop this problem we will apply the concepts related to the conservation of momentum. For this purpose, the initial momentum will be equivalent to the initial momentum of the two objects when they have the same speed. Mathematically this can be expressed as,
Where,
= Mass of bullet
= Velocity of bullet
= Mass of wooden block
Velocity of Wooden block
Inititally 
then we have that the expression can be rearrange to find the velocity of the bullet,
Replacing with our values
Therefore the velocity of the bullet before striking the block is 319.6m/s
