Page 149 - Volt Elevate The World Around Us Book 4

The Rainbow

A rainbow is formed when sunlight passes through raindrops
in the sky after rain. The raindrops act like tiny glass prisms.
They bend and spread the sunlight into different colours.

This process is called dispersion of light.
rainbow
A rainbow usually appears when it rains and the sun shines at the same time. It looks like
a big, colourful arc across the sky. It always has seven colours, which appear in the same

order every time, i.e. violet, indigo, blue, green, yellow, orange and red.

The Horizon

When we look far away in the distance, it seems as if the
Earth and the sky are touching each other at a line. This line
is called the horizon. It is where the land (or sea) and the sky

seem to come together. horizon

The horizon is also the place where we see the sun rising and setting. The rising and
setting of the sun at the horizon is only an appearance because in reality the Earth is
rotating.

Formation of Shadows

A shadow is formed when the sunlight gets blocked by an object on Earth. A shadow
has some characteristics. Let’s learn about them.

y Irrespective of the colour of the object, the shadow is always dark or black in colour.
y A shadow is always formed on the side opposite to the direction of sunlight.

y A shadow shows only the outline or shape of the object and no other details.
y The size of a shadow may be smaller or bigger than the object. The size of a shadow
depends on the following.

y The distance between the object and the screen where it is formed
y The distance between the object and the source of light

The length of a shadow is longer in
the morning and evening whereas,

it is the shortest at noon. This is
because sun rays fall in an inclined
manner in the morning and evening
whereas, the sun is directly over our

heads at noon. morning shadow noon shadow

139