The Disease: The Disease: Bacillus cereus can cause two distinct types of illnesses: 1) a diarrheal illness with an incubation time of approximately 10 to 16 hours, and 2) an emetic (vomiting) illness with an incubation time of one to six hours.
radius of curvature. n. (Mathematics) the absolute value of the reciprocal of the curvature of a curve at a given point; the radius of a circle the curvature of which is equal to that of the given curve at that point. See also centre of curvature.
The radius of curvature is the radius of the sphere from which the mirror was cut. The distance from the vertex to the focal point is known as the focal length - f. As the focal point is the midpoint of the line joining the vertex and the center of curvature, the focal length is one-half the radius of curvature. Any ray travelling parallel to the principal axis on its way to the mirror will pass through the focal point upon reflection. Because the sun is such a large distance from the Earth, all light rays from the sun are travelling parallel to each other.