Question

every point on a wave front can be considered as a point source of secondary wavelets which spread out in all directions--this is the ____principle.

Answer 1

Answer: Huygen's principle

Explanation: also called Huygens-Fresnel principle, a statement that all points of a wave front of sound in a transmitting medium or of light in a vacuum or transparent medium may be regarded as new sources of wavelets that expand in every direction at a rate depending on their velocities.