1. Suntanning produces cellular damage in the skin. Why is ultraviolet radiation capable of producing this damage whereas visible radiation is not? 2.  Why doesn’t the sharpness of the image in a...

1. Suntanning produces cellular damage in the skin. Why is ultraviolet radiation capable of producing this damage whereas visible radiation is not?

2.  Why doesn’t the sharpness of the image in a pinhole camera depend on the position of the viewing screen?