**34. A concave mirror has a focal length of 30.0 cm. The distance between an object and its image is 45.0 cm. Find the object and image distances, assuming that (a) the object lies beyond the center of curvature and (b) the object lies between the focal point and the mirror.

 

If object is beyond the center of curvature, the image will be real and therefore positive.

 

The distance between object and image distance is

 

Solve for one, let’s do image distance

 

Now use mirror equation

 

 

 

 

 

 

Solve the quadratic formula

 

 

 

 

 

Object distance is 90.0 cm then image distance would be 45.0 cm and the image will be real and inverted.  If we use object distance is 15.0 cm, then it is between focal point and mirror and the image would have to be negative and it would be 30.0 cm.

 

For Object > Radius of curvature

For Object between Focal length and mirror

 

 

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This page last updated on June 29, 2018