The radius of curvature of a concave mirror is $40 c m$ . Determine its focal length.

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Solution

For a concave mirror, the focus lies at a distance half the radius of curvature of the mirror, in front of the mirror.
The radius of curvature, $R = 40 c m$
Hence, the focal length, $f = \frac{R}{2}$
$f = 20 c m$

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The radius of curvature of a concave mirror is 40 cm. Determine its focal length.

For a concave mirror, the focus lies at a distance half the radius of curvature of the mirror, in front of the mirror.The radius of curvature, R=40 cmHence, the focal length, f=R2f=20 cm

The radius of curvature of a concave mirror is $40 c m$ . Determine its focal length.

For a concave mirror, the focus lies at a distance half the radius of curvature of the mirror, in front of the mirror.
The radius of curvature, $R = 40 c m$
Hence, the focal length, $f = \frac{R}{2}$
$f = 20 c m$