Answer:
The umbra, penumbra and antumbra are three distinct parts of a shadow, created by any light source after impinging on an opaque object. Assuming no diffraction, for a collimated beam (such as a point source) of light, only the umbra is cast.
Explanation:
Answer:
The answer to this question is A and C
Explanation:
After the age eligibility rule was instituted by the Women's Tennis Association, career lengths increased significantly. Before the rule was established, there were concerns that athletes who engage in professional sports at a very young age experience shortened careers and in most cases leave prematurely before even getting to their peak. However, the rule has helped in reducing premature retirement immensely.
