An object that is 4.00 cm tall is placed 18.0 cm in front of a concave mirror having a focal length of 20.0 cm. What is the location of its image in relation to the mirror and what are its characteristics?
A) 20 cm on the same side of mirror, real, 10.0 times bigger
B) 18 cm on the same side of mirror, virtual, 2.25 times bigger
C) 180 cm on the other side of mirror, virtual, 10.0 times bigger
D) 10 cm on the other side of mirror, virtual, 10.0 times bigger
E) 180 cm on the other side of mirror, real, 6.00 times bigger

Question

Quizplus · Accepted Answer

To find the image location and characteristics, we use the mirror equation and magnification formula. The mirror equation is $ \frac{1}{f} = \frac{1}{d_o} + \frac{1}{d_i} $, where $f$ is the focal length, $d_o$ is the object distance, and $d_i$ is the image distance. Plugging in the given values ($f = -20.0$ cm for a concave mirror, $d_o = -18.0$ cm since the object is in front of the mirror), we solve for $d_i$, which gives us $d_i = 180$ cm, indicating the image is formed on the other side of the mirror, which is characteristic of a virtual image in this context. The magnification ($m = -\frac{d_i}{d_o}$) gives us a value of 10, indicating the image is 10 times bigger than the object.

An Object That Is 4