LIGHT AND SHADOWS

• Light helps us to see objects.

• Luminous objects:
• Objects that give out or emit light of their own.
• Ex: Sun, Torch, Glow-worm, etc.
• Non-Luminous objects:
• Objects that do not give out or emit light of their own.
• Ex: Chair, Shoe, etc.
• We see other non-luminous objects, when light from a luminous object falls on these and then travels towards our eyes.

• Opaque objects:
• Objects through which we cannot see at all.
• Objects through which light cannot pass.
• Ex: Book, Stone, etc.
• Translucent Objects:
• Objects through which we can see, but not very clearly.
• Objects through which light can pass partially.
• Ex: Polythene, Scale, etc.
• Transparent Objects:
• Objects through which we can see very clearly.
• Objects through which light can pass easily.
• Ex: Air, Glass, etc.

SHADOWS

• To see a shadow, we need
• a source of light
• an opaque object
• a screen.
• When light from a source is not able to pass through an opaque object to the other side, a shadow is formed on the screen.
• A shadow is obtained only on a screen (Ground, Wall, Building).

• Sometimes, shadows of an object gives an idea about its shape.
• Some other times, It may create confusion as more than 1 object has similar shadows.