Question

Answer only in one sentence
1. What is light ?
2. When do non – luminous objects become visible ?
3. When is a shadow formed?
4. Astronauts can see the Earth as a shinning ball from the outer space . How is this possible since
the Earth does not give out its own light ?
5. What is the speed of light ?

Answer 1

Explanation:

Light, or Visible Light, commonly refers to electromagnetic radiation that can be detected by the human eye. ... Light can also be described in terms of a stream of photons, massless packets of energy, each travelling with wavelike properties at the speed of light.

Answer 2

Answer:

1. Light, electromagnetic radiation that can be detected by the human eye
2. Non-luminous objects reflect the light falling on them and the reflected light are sensed by the eye and thus we are able to see non-luminous objects.
3. To form a shadow a source of light is required. It is only when light rays are obstructed we get the shadow of the object
4. Due to property of reflection of light, the Earth reflect some part of Sunlight to outer space. so Astronauts can see the Earth as a shining ball from outer space or moon. Same as we see the different phases of moon from the Earth.
5. 299 792 458 m / s

Explanation:

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