Dip a coin into the bottom of the opaque cup. Position the cup so that some of the inside of the cup is visible and the coin is not visible. Gradually pour water into the cup without changing its position in relation to the eyes. Describe and explain the observed phenomena
The coin becomes visible in a cup of water, since the rays are refracted at the border of air and water, and our eye sees the image of the coin, which appears where the continuation of the incident rays intersect.
Remember: The process of learning a person lasts a lifetime. The value of the same knowledge for different people may be different, it is determined by their individual characteristics and needs. Therefore, knowledge is always needed at any age and position.