A 20 cm tall object is located 10cm in front of a diverging lens... Ray Diagram help?

A 20 cm tall object is located 10 cm in front of a diverging lens whose focal length has a magnitude of 15 cm.

a)Draw a ray diagram for this situation. Make sure to label the principal axis with all relevant quantities, draw the correct lens, draw the image, and draw three correct light rays.

I dont understand any of this.. i've barely been taught this and my teacher assigned a take home quiz...please help? i just dont understand the concept of where the focal length or object is placed on the graph, and please be specific?

2 Answers

  • Zack M
    Lv 5
    8 years ago
    Favorite Answer

    20 cm tall is

    Height of object. Since its positive it is upright.

    10 cm from the lens is 10 cm from its vertex where the principal axis meets the lens.

    a diverging lens means its a convex mirror or a concave lens. They only have one possible image and one possible way for light to be reflected.

    The image will ALWAYS BE - Smaller, Upright and Virtual (not real)- so mathematically possible not realistically. Memorization technique is SUV i still remember it from high school.

    Principle axis is an imaginary line that cuts the mirror or lens technically in half, for a diverging (convex mirror/concave lens) note the focus and the center are virtual so they are inside the mirror.

    Where the focus and the center is located. The center is ALWAYS double the focal length.

    For mirrors and lens:

    Incident ray - Refracted ray

    Parallel to PA - through the focus ( diverging lens is two c put together one back wards creating a type of vasy look)

    Through f - Parallel to Pa

    Through C - through c

    So draw it accordingly where the 3 lines meet is where the object is, for lenses there is a thing called a primary and secondary focus.

    Perhaps this site will help they are notes ! so if your teacher hasnt taught you these will, still up from my high school days.


    Light as wave (unit 4) - Lesson 5 -Lens diagrams

  • Anonymous
    4 years ago

    im no longer doing ur hw for you. in basic terms use the len's maker's equation: (a million/p) + (a million/q) = a million/f the place p is ur merchandise's distance from the lens q is the area of the image from the lens and f is the focal length

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