Find the distance of object from a concave mirror of focal length 10 cm so that image size is four time the size of the object.

Explanation

To solve the problem of finding the distance of the object from a concave mirror of focal length 10 cm, where the image size is four times the size of the object, we will follow these steps:

### Step 1: Understand the Magnification
The magnification (m) is given by the formula:
\[ m = \frac{h_2}{h_1} \]
where \( h_2 \) is the height of the image and \( h_1 \) is the height of the object. According to the problem, the image size is four times the object size, so:
\[ m = 4 \]

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