This question is incomplete because the options are missing; here is the complete question
The ozone layer is found in which layer of the atmosphere?
A. Stratosphere
B. Mesosphere
C. Thermosphere
D. Troposphere
The correct answer is A. Stratosphere
Explanation:
The ozone layer as indicated by its name is mainly composed of Ozone (O2), this layer is essential for life because it filters ultraviolet radiation and acts as a greenhouse effect gas by trapping part of the heat from the sun. Additionally, the ozone layer is located in the stratosphere, which is the second layer of the atmosphere and can be found between 20 km to 50 km from Earth's surface. Moreover, the existence of the ozone layer in the stratosphere makes the temperature increase with height due to the radiation of the sun filter by ozone.
To solve this problem we will apply the concept of magnification, which is given as the relationship between the focal length of the eyepieces and the focal length of the objective. This relationship can be expressed mathematically as,

Here,
= Magnification
= Focal length eyepieces
= Focal length of the Objective
Rearranging to find the focal length of the objective

Replacing with our values


Therefore the focal length of th eobjective lenses is 27.75cm
Answer:

Explanation:
Refractive Index: It is a measure to find how fast the light travels through a medium. It is ration of the speed of light in vacuum to speed of light in the medium. Speed of light is not constant and varies depending on the density of the medium.
In vacuum the speed of light is 300000 km/s and is denoted by c. When the light beam enters any medium the speed will decrease. Here it is given that the speed in plastic is v. Thus the refractive index(n) is given as:

It is a dimensionless no.
The "weight" is the name we give to the force of gravity on the object. They're the same thing.
Answer:
v = sqrt[2*(F*h*cot(theta)-mgh)/m]
Explanation:
Work = KE + Ug
F*r=1/2mv^2+mgh
1/2mv^2=F*r-mgh
v=sqrt[2(F*r-mgh)/m]
r=h/tan(theta)=h*cot(theta)