Discover the Focal Length of a Convex Mirror Using Object and Image Distance

[Bk8907]

Convex mirror. PLEASE HELP!

Homework Statement

An object 30 cm tall is placed 20 cm in front of a convex mirror. If the height of the image is +10 cm, find the focal length of the mirror.

Homework Equations

The Attempt at a Solution

I know to use 1/f = -(Image distance from V) / Object distance from V. But, now they tell me how tall they are. How to solve now?

 

[andrevdh]

http://www.physicsclassroom.com/Class/refln/u13l4a.html"

 

[m2003]

I would first verify the information given in the problem to ensure that it is accurate and complete. From the given information, we know that the object distance (u) is 20 cm, the image distance (v) is -10 cm (since the image is virtual and on the same side as the object), and the height of the object (h) is 30 cm.

Using the mirror equation 1/f = 1/u + 1/v, we can substitute in the values and solve for the focal length (f).

1/f = 1/20 + 1/-10

1/f = -1/20

f = -20 cm

The negative sign indicates that the focal length is on the opposite side of the mirror as the object and image.

I would also consider the limitations and sources of error in this experiment. For example, the mirror may not be perfectly spherical, which could affect the calculated focal length. Additionally, the measurements of the object and image distances may not be precise, leading to some degree of uncertainty in the calculated focal length. These factors should be taken into account when interpreting the results of this experiment.