*71. ssm An object is placed 20.0 cm to the left of a diverging lens (f = - 8.00 cm). A concave mirror (f = 12.0 cm) is placed 30.0 cm to the right of the lens. (a) Find the final image distance, measured relative to the mirror. (b) Is the final image real or virtual? (c) Is the final image upright or inverted with respect to the original object?

 

So let’s find the image of the first lens and make that the object for the second lens and then you can find the final image.  The image of the diverging lens.

 

 

The object distance for the second lens is found from

 

 

Now find the second image using this object distance

 

 

 

The fact that the answer is positive implies the second image is real and located 18.1 cm to the left of the concave mirror!

 

The final image is real.  Since the first image is virtual the object for the mirror is upright.  A real image of an upright object from a concave mirror will be inverted.

 

 This means 18.1 cm to left of concave mirror

The final image is reall, and it is inverted.

 

 

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This page last updated on July 7, 2018