Question

Janice

Answer 1

Magnification M is given as

Here, h and h' are the height of the object and the image. p and q represent the distance of the object and the image from the mirror. We are assuming that the location of the Janie's pinky from the mirror is p₁

Janie's pinky is 5.85 cm and inverted image is 2.10 cm. Therefore

Since the image is inverted so we are introducing a negative sign for magnification

For the case if the object is bring closer to the mirror p₂ = p₁ -1.2 cm then the magnification becomes

Since the image is inverted so we are introducing negative sign

Now we have to find p_1. To do so

Solving the above

Rewriting it as

The distance between the Janie's pinky and the mirror is 4.14 cm.

In order to calculate focal length we need to find q

Focal length