What is the image distance of a 4 cm tall object placed 40 cm from a concave mirror having a focal length of 10 cm?

Choose one answer.
a. -13.3 cm
b. 13.3 cm
c. -40.0 cm
d. 40.0 cm

f = 10 c,

!/Do + !/Di = 1/f

Di is the object distance.

1/40 + 1/Di = 1/f

1/Di = 1/f - 1/Di = 1/10 - 1/40 = 3/40

Di = ___ cm

The object height (4 cm) does not matter when location image location.

1/f=1/v+1/u

where f=focal length
v=image distance
u=object distance
1/10=1/v+1/40
1/10-1/40=3/40
3/40=1/v cross multiply
3v/3=40/3 divide both sides by 3
v=13.3 cm

suppose you place a 5.0cm tall spring in front of a concave mirror. the mirror has a focal length of 24cm. the spring forms an image that appears to be at the same position as the spring,but the image is inverted. where did you place the spring? how tall is the springs image?

To find the image distance of an object placed in front of a concave mirror, we can use the mirror formula:

1/f = 1/v - 1/u

Where:
f is the focal length of the mirror,
v is the image distance,
u is the object distance.

In this case, the object distance u is given as 40 cm, and the focal length f is given as 10 cm.

Let's substitute these values into the formula:

1/10 = 1/v - 1/40

Now, let's solve for v:

Multiply both sides by 40v to eliminate the fractions:

40v/10 = 40v/v - 40v/40

4v = 40 - v

Add v to both sides:

4v + v = 40

5v = 40

v = 40/5

v = 8 cm

Therefore, the image distance is 8 cm.

Since the image distance is positive, we can conclude that the image is formed on the same side of the mirror as the object.

So, the correct answer is d. 40.0 cm.