Respuesta :
Answer:
Focal length of the eye-lens is 2.0 cm
Explanation:
Given:
An eye-lens system which will follow converging lens (convex lens) sign conventions and knowing that lens-retina distance is the image distance.
Object distance, [tex]u[/tex] = [tex]-\infty[/tex]
Image distance, [tex]v[/tex] = [tex]2.0[/tex] cm
We have to find the focal length.
Lets say that the focal length is [tex]f[/tex] .
Lens Formula:
⇒ [tex]\frac{1}{f} =\frac{1}{-u} +\frac{1}{v}[/tex]
Sign-convention:
We will follow the Cartesian coordinate,placing the lens at the origin of the plane, optical center is at [tex](0,0)[/tex] now as the object will be towards negative x-axis so it is negative others are on the right side of the origin so they are positive.
Using the lens formula:
⇒ [tex]\frac{1}{f} =\frac{1}{-u} +\frac{1}{v}[/tex]
⇒ [tex]\frac{1}{f} =\frac{1}{-\infty} +\frac{1}{2.0}[/tex]
⇒ [tex]\frac{1}{f} =0+\frac{1}{2.0}[/tex] ...as [tex]\frac{1}{\infty}=0[/tex] and there is no [tex]-0[/tex] so it is zero only.
⇒ [tex]f=2.0[/tex] cm
So the focal length is 2.0 cm with two significant figures.
