Final answer:
To calculate the focal length of a concave mirror, use a flashlight to shine light onto another turned-off flashlight's curved mirror or a car headlight's concave mirror, then estimate the point of focus. This point is the focal length, which is half the radius of curvature.
Step-by-step explanation:
To experimentally calculate the focal length of a concave mirror directly, one can use a simple and practical method. First, find two flashlights and identify the curved mirror in one of them. Shine the beam of the first flashlight onto the second one, which should remain turned off. By observing the point at which the reflected light focuses, you can estimate the focal length of the mirror. Another option is to shine a flashlight onto the concave mirror behind a car headlight with the headlight switched off to determine its focal length. The focal point is where the parallel rays converge, which is usually at the midpoint of the radius of curvature, thus the focal length is half the radius of curvature of the mirror.