Understanding Lens and Mirror Equations: Focal Length, Object and Image Distance

[indiansfan4life]

A) A student places a light bulb 30 cm in front of a concave mirror. A real image of the bulb is found 6 cm in front of the mirror. What is the focal length of the mirror?

my answer was 5 cm

Given
-----
do=30cm
di=6cm
f=?

f=dodi/do+di

f=30*6/30+6

=5

B) If a light bulb is place 12 cm in front of a concave mirror with a focal length of 3 cm. How far in front of the mirror will the real image of the light bulb be found?

my answer was 4 cm

Given
-----
do=12cm
f=3cm
di=?

di=dof/do-f

di=12cm*3cm/12cm-3cm

=4

H) How did the location of the image change as you moved the object (light bulb) toward a mirror?

increased

I) how did the size of the image change as you moved the object toward the mirror?

increased in size


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A) A student places a light bulb 12 cm in front of a double convex lens. A real image of the bulb is found 3 cm on the other side of the lens. What is the focal length of the lens?

my answer was 2.4 cm

Given
-----
do=12cm
di=3cm
f=?

f=dodi/do+di

f=12*3/12+3

=2.4

B) A light bulb is place 30 cm in front of a double convex lens with a focal length of 6 cm. How far on the other side of the lens will the real image of the light bulb be found?

my answer was 7.5 cm

Given
-----
do=30cm
f=6cm
di=?

di=dodf/do-f

di=30*6/30-6

=7.5

H) How did the location of an image change as you moved the object (light bulb) toward a lens?

decreased

I) How did the size of the image change as you moved the object toward the lens?

it also decreased in size


thanks

 

[indiansfan4life]

bump, please I need this checked

 

[indiansfan4life]

please help me out and check

 

[indiansfan4life]

Last bump for the night, hopefully someone helps

 

[deficiency4math]

ill bump for u

 

[indiansfan4life]

Thanks, hopefully someone sees this.