+0  
 
0
192
2
avatar+37 

A reflecting, spherical Christmas tree ornament has a diameter of 7.0 cm. A child looks at the ornament from a distance of 16 cm. 

 

Where is the image located?

 Mar 13, 2018
 #1
avatar+17332 
+2

This is a convex mirror.   The focal point is MIDWAY betwen the center of curvature and the lens surface and is NEGATIVE

So for this mirror  f = -1.75  (1/2 of the RADIUS)    It will produce a virtual image on the same side as the focal point (opposite the side of the OBJECT ....the child's face) so the distance result will be negative thusly:

 

1/f  =  1/do + 1/di          do = distance to the object = 16cm    f = - 1.75     solve for di

 

-1/1.75 = 1/16 + 1/di

-1/1.75 - 1/16 = 1/di

di = - 1.58 cm

 Mar 14, 2018
 #2
avatar+37 
+1

Thank you!

cmoore  Mar 14, 2018

13 Online Users

avatar
avatar
avatar
avatar
avatar
avatar