A concave spherical mirror can be used to project an image onto a sheet of paper, allowing the magnified image of an illuminated real object to be accurately traced.

Question

A concave spherical mirror can be used to project an image onto a sheet of paper, allowing the magnified image of an illuminated real object to be accurately traced. If you have a concave mirror with a focal length of 8.1 cm, where would you place a sheet of paper so that the image projected onto it is twice as far from the mirror as the object is? Is the image upright or inverted, real or virtual? What would the magnification be?

location ___

real [ ]	virtual [ ]
erect [ ]	inverted [ ]

Magnification ___

Answer 1

One of the important aspects of optics is the fact that if the image can be projected, it must be real.

If we assume object distance = do, the image distance is therefore 2d0

We get 1/f=1/do+1/2d0

The question did not ask for the image distance but it could be calculated from this.

Also since the image is real it has a positive value in the mirror equation. Using the Magnification equation we get

M=-di/do, As both di and do are positive the magnification is negative which means it is inverted.