ap physics b, question, light2?

Question

An object of height 2 mm is placed 40 cm to the left of a converging lens whose focal length has magnitude 20 cm
a. completely describe the image. Is the image real/ virtual, upright.inverted? What is the location, heightm and magnification of the image?

Answer 1

Ok, let's remember this equation :

1 / p + 1 / q = 1 / f

p = object distance

q = image distance

f = focal lenght

1 / 40 + 1 / q = 1 / 20

q = 40 cm

It's a real imagne, 40 cm to the right of the lens.

Let's find the magnification :

m = -q / p = -40 /40 = -1

-1 = x / 2 mm

x = height of the image, and it's the same 2mm but inverted.

That's it, hope that helped