How can I heat up 40mL of water in a beaker using a black box, mirrors, a magnifying glass and aluminum foil?

Question

those are the materials I have to heat up the water, does anyone know how to improve it?

Answer 1

On a clear sunny day, near an open window, arrange the black box on its side, with the opening facing the window. Put the aluminum foil inside the bottom of the black box. Then put the beaker of 40ml water ontop of the center of the foil. With the mirror, aim the sunlight towards the beaker's bottom center. With the magnifying glass between the beaker and mirror, angling it as necessary and moving it back and forth till you have a pinpoint of light at the center of the bottom of the beaker.

Happy heating...hope you have strong arms or put the magnifying glass on a support, without blocking the path of sunlight, to take place of your arms.

Answer 2

Theoretically, it would work. Mirrors would be a much, much easier bet to pull off, though. There are solar furnaces that do this in the world, but not on the scale you're talking about. It'd take lots of space, I used to imagine this scenario, too, when I was first introduced to optics. It's not practical for magnifying glasses because the size and weight of the glass lenses gets so large they can't support their own weight, they'd distort under their own weight. Arrays of mirrors, however, work pretty well for this on a smaller scale than you're describing.

Answer 3

use the mirrors to direct light onto the magnifying glass. wrap the beaker in the foil.

Answer 4

Use your magnifying glass to focus the light on the black box and heat it up.

Answer 5

poursome hot water into beaker when teacher not looking & claim "thermal heat" induction.