Lenses

Types of lenses: How light passes through lenses :
 * Lenses**

**//__F=R/2__//**
Each lens has a center of curvature. Which can be used to find the focal length of the lens. __**F=R/2**__. Focal length=half of the center of curvature.

1.Example: If a lens has a center of curvature of 10cm, what is the focal length? Solution: a.Write out Formula: F=R/2 b.Plug in 10cm into center of curvature spot: F=10cm/2 c. Divide the center of curvature by 2 to get the focal length: F=5cm

2.Example: If a lens has a focal length of 24cm, what is the center of curvature? Solution: a.Write out Formula:F=R/2 b.Plug in the Focal Point: 24cm = R/2 c.Multiply each side by 2: 24cm(2) = R d.Answer is 48cm: 48cm = R

Another equation that is used with lenses is the thin lens equation. The thin lens equation, __**1/F=1/do+1/di**__ or __**1/F=1/p+1/q**,__ can be used to find the focal length, Distance from the lens to the object, and the distance from the lens to the image.
 * //__Thin Lens Equation__//**

1.Example: If a lens has an object 2cm away and an image 5cm away, what is the focal length? Solution: a.Write out Formula: 1/F= 1/p+1/q b.Plug in the 3 cm in the p slot and 5cm in the q slot: 1/F=1/2+1/5 c.Add the fractions together: 1/F=7/10 d.Invert each side: F=10/7cm

2.Example: If a lens has a focal length of 5m and the distance to the object is 10m, what is the distance to the image? Solution: a.Write out Formula: 1/F= 1/p+1/q b.Plug in 5m for the Focal length and 10cm in the p slot: 1/5=1/10+1/q c.Subtract 1/10 on both sides: 1/5-1/10=1/q d.Subtract: 15/50=1/q e.Reduce the Fraction: 1/q=3/10 f.Invert both sides: q=10/3

3.Example: If a lens has a focal length of 20mm and an image formed at 60mm, what is the distance of the object? Solution: a.Write out Formula: 1/F= 1/p+1/q b.Plug in 20 into the F spot and the 60 into the q spot: 1/20=1/p+1/60 c.Subtract 1/60 from both sides:1/60=1/p d.Subtract: 1/30=1/p e.Invert both sides: p=30mm

The thin lens equation can be used for any lens, no matter what type. The only thing that will change for each type of lens would be the behavior of the image. Some could be upside down, some right side up, some the same size, some bigger, some smaller, some images could be real, and other could be virtual.

__//**Magnification Equation**//__
1.The Magnification equation is **__M= -q/p__** this equation is the same for lenses and mirrors Example: If p is 20cm and q is -5.71 cm what is the Magnification ? a.Write equation: M= -q/p b.Plug in 20 for p and -5.71 for q: M= -(-5.71/20) c.Divide and get answer: M= .286

=**//__Ray Trace Diagrams__//**=
 * //__Click Here for complete explanation of Lenses Ray Trace Diagrams__//**


 * //__Convex Lens__//**
 * //__Concave Lens__//**


 * //__2 Lenses Ray Trace Diagram__//**

=//__References__//= Pictures: @http://www.physicsclassroom.com/class/refrn/u14l5ea4.gif @http://em-outreach.ucsd.edu/web-course/Sec-I.A/Image34.gif @http://upload.wikimedia.org/wikipedia/commons/thumb/a/a7/Lenses_en.svg/450px-Lenses_en.svg.png @http://www.nightlase.com.au/education/optics/Images/lens.gif Helping Websites: @http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/raydiag.html @http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/simmag.html @http://www.hirophysics.com/Anime/thinlenseq.html @http://hyperphysics.phy-astr.gsu.edu/hbase/geoopt/lenseq.html

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