Question

The focal length for a spherical convex mirror is –20 cm. What is its radius of curvature?

Answer 1

Answer:

40 cm

Explanation:

The focus of a spherical convex mirror is the point at which the rays of an object converge in the infinite, it is also the point at which an object must be placed so that its image is formed in the infinite. The distance from the focus to the origin is called the focal length and is called f. It is related to the radius of the mirror, R, according to:

$f=-\frac{R}{2}$

rewriting for R:

$R=-2f=-2*-20cm=40 cm$.