Concave and Convex Mirrors

Objective: Explore the images formed by convex and concave mirrors.

Equipment:

• Convex mirror
• Concave mirror
• An object
• Ruler

Procedure:

     convex mirror- A marker was placed in front of the convex mirror.The image appears smaller than the actual object but the object is upright. The image seems further from the mirror then the actual object.        With a ruler placed normal to the mirror's center  we held the mirror a distance d0=0.50m. The height of the marker (our object) was h0=0.12m. Measuring (on the mirror) the size of the image of the marker gave us hi=0.067m when the object is moved closer the image appears bigger and it gets smaller as it moves away.

     concave mirrors- the object was now placed in front of a convex mirror. The object appeared inverted and larger. When the object moved closer it appears upright, and still magnified. The image also appears closer to the mirror then the actual object. Using the ruler  we again placed it 0.50m from the center and we observed an inverted height of 0.21m.

Analysis: This phenomenon can be explained by using a diagram of light rays being reflected off the pen.

 For the convex mirror you see that the point where these rays intersect is where the top of the marker's image appears and this agrees with our observation

For the concave mirror we see the focus and center of the sphere is outside of the mirror. Using the rays it can be seen that the object appears to be inverted which also agrees with our observation.

From this it can be concluded that the image size and orientation depend on the focus or center of the spherical mirror.