convex mirror

Question

A diverging (convex) mirror of focal length 12.0 cm produces an image for an object that is located 20.0 cm from the mirror.

a)The distance to the image is: ___ cm

b)The magnification is ____x 

c)The image produced will be:

 

Question 9 options:

	real
	virtual

 

Answer 1

a)

Focal Length f = 12 cm

Distance from the mirror to the object d_object = 20 cm

Distance to the image = d_image

Formula : (1/f) = (1/d_object) + (1/d_image)

(1/12) = (1/20) + (1/d_image)

(1/d_image) = (1/12) - (1/20)

(1/d_image) = (1/12) - (1/20)

By using zero product property : If AB = 0 then A = 0 , B = 0. ( LCM of 12,20 is 60 )

(1/d_image) = (20-12)/60 = 8/60 = 1/7.5

d_image = 7.5 cm.

Distance to the image is 7.5 cm.

Answer 2

c)

The properties of image in convex mirror :

1. Virtual image.
2. Upright image.
3. Smaller than the object.

The image produced will be Virtual ( Option(b) )

Answer 3

b)

The magnification M = -(d_image)/(d_object)

M = -7.5/20 = -0.375

The magnification is -0.375x.