1561. На границе двух сред 1 и 2 (рис. 394) световой луч SA изменил свое направление. Начертите в тетради угол падения и угол преломления луча. 1562. Девочка видит Луну под углом 30° над горизонтом. Если мыс-ленно провести прямую линию от глаза девочки в сторону видимого диска Луны, то можно ли утверж-дать, что Луна находится на этой прямой? Объясните почему. 1563. Узкий параллельный световой пучок (рис. 395) падает на гладкую поверхность воды, как показано на рисунке. Начертите в тетради дальнейший ход отраженного света и примерный ход преломленного света. 1564. Узкий световой пучок (рис. 396) направлен к гладкой поверхности воды, как показано на рисунке. Начертите в тетради примерный ход пучка света, вышедшего в воздух, и постройте отраженный от поверхности воды пучок света. 1565. Даны две среды (1 и 2) из кварца и каменной соли (рис. 397). На границе их раздела угол падения луча равен углу преломления. Начер-тите в тетради дальнейший ход узкого пучка света, направленного к границе раздела этих сред.
To solve this problem, we need to apply the laws of reflection and refraction. Firstly, we can draw the normal line perpendicular to the surface of the water, which will help us determine the angle of incidence and angle of refraction. For the incident angle of the light beam, we can use the given value of 30°. To find the angle of refraction, we can use Snell's law, which states that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is equal to the ratio of the indices of refraction of the two mediums. In this case, since the incident and refracted angles are equal, the indices of refraction for the two mediums must also be equal. Therefore, the refractive index of water and air must be the same, and we can use the approximate value of 1.33.Once we have determined the angles of incidence and refraction, we can use the laws of reflection and refraction to plot the path of the light beam. The incident ray will be reflected at an equal angle to the normal line, and the refracted ray will be bent towards the normal line. By drawing these paths accurately, we can visualize the direction of the light beam as it exits the water and enters the air again. This will give us the final path of the light beam in the air.
Hence, we can conclude that the path of the light beam will be almost parallel to the surface of the water, but will be slightly bent upwards towards the normal line due to refraction. We can also notice that the incident, reflected, and refracted rays will form a straight line, indicating that the Moon will appear to be directly above the girl's line of sight. Therefore, we can confidently state that the Moon is indeed on the same straight line drawn from the girl's eye towards its visible disk.
Overall, this problem helps us understand the principles of reflection and refraction in different mediums, as well as how light behaves when it enters and exits different mediums. It is important to understand these concepts to explain various optical phenomena and to design optical devices such as lenses and mirrors.
