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Reflected Motion

المؤلف:  GEORGE A. HOADLEY

المصدر:  ESSENTIALS OF PHYSICS

الجزء والصفحة:  p-62

2025-11-02

604

If an elastic ball strikes against a fixed body, it will rebound. This is called reflected motion, and is caused by the reaction of the body against which it strikes. If a moving body is not elastic, the reaction of the body against which it strikes will flatten it, as, for example, when a ball of putty is dropped upon the floor. If both the bodies are highly elastic, the direction of the rebound will be such that the angle of reflection will equal the angle of incidence. This is the Law of Reflection, and may be verified as follows:

FIG.1

Demonstration. - Place a strip of board on its edge upon a table resting against the wall. Roll an elastic ball across the table along the line AB (Fig. 1) against the board. From B, where the ball strikes, draw BD perpendicular to the board. Then the angle CBD, the angle of reflection, will be found equal to the angle ABD, the angle of incidence. (The path of the ball can be readily traced by dusting the table with crayon dust.)