Max is playing in the backyard, focuses the sunlight with a magnifying lens to burn peanuts
in a sieve, which his mother left in the sunlight for drying. His mother
shouts to him "Be careful! Do not burn yourself!" Max shouts back "Ok.
How hot is it? Can I boil water with the lens?" Max's mother knows
that the solar system using the sunlight can boil water. But she has no idea how
hot the focus can be. That is, what is the upper limit of the temperature
the focusing sunlight system can reach? Can you help her?
What is known:
Focusing the sunlight with a magnifying lens