Real and virtual images.<span> In a dark room one can form an image of a candle flame on a white screen by letting the rays from the candle pass through a small opening. See Fig. 1. This idea is used in the pinhole camera. The pinhole camera is simply a light-proof box with a tiny pinhole in the front and photographic film stretched across the rear wall. See Fig. 2. One uncovers the pinhole for a minute or so, then covers it back up, to take a picture. If it is held steady, it can take a good picture. If one replaces the pinhole with a lens, the intensity of the incident light is increased and a sharp image can be recorded in a fraction of a second. The image formed by a pinhole or a lens is formed by incident rays of light on a surface and stands in contrast to another kind of image — the kind of image formed by a mirror. The image formed by a mirror is not real, it is an illusion formed by the way the light reflects off the mirror. The image seen in a mirror looks three dimensional and real but we know there is nothing where the image appears to be. An image such as that formed by a pinhole or lens is called a </span>real image<span>. An image such as that formed by a mirror is called a </span>virtual<span> image</span>
Annually 126.0 million metric tons of soil nutrients are lost.
<u>Explanation</u>:
- By the given data we can identify the loss of soil nutrients in the United States. In the first year, a total of 1.0 million soil nutrients are lost.
- After that in the second year, the loss has doubled. 10.0 million metric tons of soil nutrients are lost.
- In the third year, 16.0 million soil nutrients are lost in the US.
- In the final year, 90.0 million soil nutrients are lost. It is a very huge loss. By calculating all the above , a total 126.0 million of soil nutrients in the US are lost annually.
