Exploring the Focal Point of a Concave Mirror

[afcwestwarrior]

I know that when the focal point is in the inside of a concave mirror. The focal point is greater than zero, and the radius is greater than zero and the lateral magnification is greater than zero.

So if the focal point is on the outside of this concave mirror. Would the focal point be less than zero, and would the radius be less than zero, and would the lateral magnification be less than zero.

 

[mgb_phys]

Sorry not sure what you mean, the focal length of a concave mirror is half the radius of curvature.

see http://www.glenbrook.k12.il.us/GBSSCI/PHYS/class/refln/u13l3a.html

 

[nlightner]

Yes, you are correct. When the focal point is on the outside of a concave mirror, the focal point would be considered negative, as it is behind the mirror surface. The radius of curvature would also be considered negative, as it is measured from the center of curvature to the mirror surface. And the lateral magnification would be less than zero, indicating that the image formed is inverted compared to the object. This is due to the fact that light rays coming from a distant object will converge at the focal point on the opposite side of the mirror. It is important to note that the focal point and radius of curvature are always considered positive when they are on the same side as the object. Thank you for exploring this concept with me.