Sherlock Holmes examines a clue by holding his magnifying glass (with
a focal length of 15.0 cm) 10.0 cm away from an object. Find the image
distance and the magnification. Describe the image that he observes.

Distance: -30.0 cm; image is virtual, upright, enlarged

Explanation:

We can find the distance of the image using the lens equation:

where:

f = 15.0 cm is the focal length of the lens (positive for a converging lens)

p = 10.0 cm is the distance of the object from the lens

q is the distance of the image from the lens

Solving for q,

The negative sign tells us that the image is virtual (on the same side of the object, and it cannot be projected on a screen).

The magnification can be found as

The magnification gives us the ratio of the size of the image to that of the object: since here |M| = 3, this means that the image is 3 times larger than the object.

Also, the fact that the magnification is positive tells us that the image is upright.

the electric field is a “force field” around a charged object that illustrates the direction the electric force would push an imaginary