Optics
Learning physics
and chemistry
easily and freely - Science for elementary school, middle school and
high school
Free online optic lesson for elementary school, middle school and high school.
Shadows, lunar eclipses and phases of the moon
Formation of shadows
1) What is a shadow ?
When an opaque object is lighted, some areas, located behind the object, don't receive light and form the shadow of the object.
2) Core shadow and cast shadow
When an opaque object is lighted, two kind of shadows can be distinguished:
- The core shadow is the part of the object that doesn't receive light. This part is at the opposite side of the light source.
- The cast shadow consist of
- The core shadow is located on a surface behind the object (screen, wall, floor etc.) that doesn't receive light. This shadow has a shape that reproduces contours of the lighted object.
As for the space between core shadow and cast shadow, it can be called " cone shadow ".
Example:
a
sphere lighted by a tiny light source
| Science class |
| Optics lessons |
Light sources - Types of light sources - Why can we see objects ? Propagation of light - Rectilinear propagation of light - Beams of light - Speed of light - Light and distances Shadows, lunar eclipses and phases of the moon - Formation of shadows - The Moon and eclipses Colored lights - color of objects - Decomposition of white light - Colored lights - Color of objects Image formation - Thin lenses - Thin converging and diverging lenses - Image formation by thin lenses - Vision and eyes |
|
|
©2021 Physics and chemistry