JAMB - Physics (2005 - No. 2)
The sharpness of the boundary of the shadow of an object is determined by the
intensity of light striking the object
rays of light passing through the object
nature of the object
opacity of the object
解释
The characteristics of a shadow are dependent on the intensity of the light source. A hard light will produce a shadow with a sharp edge, a soft light will produce a shadow with a more blurry edge.