A point light source lies on the principal axis of a concave spherical mirror with radius of curvature 160 cm. Its image appears to be back of the mirror at a distance of 70 cm from the mirror. Determine the location of the light source.

Explanation

To determine the location of the point light source in relation to a concave spherical mirror, we can follow these steps:

### Step 1: Identify the given data
- Radius of curvature (R) = 160 cm
- Image distance (v) = -70 cm (the negative sign indicates that the image is formed behind the mirror)

### Step 2: Calculate the focal length (f)
The focal length (f) of a concave mirror is given by the formula:
...