Question

A light bulb is placed 20 cm in front of a concave mirror with a focal length of 8 cm. How far from the mirror will the image of the light bulb be focused? _______________ Show your work:

Answer 1

The image of the light bulb placed 20 cm in front of a concave mirror with a focal length of 8 cm, is focused 11.43 cm in front of the mirror.

Step-by-step explanation:

To calculate the distance where the image of the light bulb will be focused by the concave mirror, we use the mirror equation which is 1/f = 1/v + 1/u. The focal length (f) is 8 cm (which is considered as 'negative' because it's on the front side of mirror), the object distance (u) is -20 cm. Substituting these values into the mirror equation, we find: 1/v = 1/-8 + 1/-20. After solving this, we find that v = -11.43 cm. In the context of mirrors, a negative image distance means that the image formed is a real image on the same side as the light source, so the image of the light bulb is focused 11.43 cm in front of the mirror.

Learn more about Concave Mirrors

Answer 2

13.3 cm

Step-by-step explanation:

Mirrors work using the principle of refraction.

We can solve this problem by using the mirror equation:

`(1)/(f)=(1)/(p)+(1)/(q)`

where

f is the focal length of the mirror

p is the distance of the object from the mirror

q is the distance of the image from the mirror

In this problem, we have:

f = 8 cm is the focal length

p = 20 cm is the distance of the light bulb from the mirror

Solving for q, we find the distance of the image from the mirror:

`(1)/(q)=(1)/(f)-(1)/(p)=(1)/(8)-(1)/(20)=0.075\\q=(1)/(0.075)=13.3 cm`