Let’s make a Rainbow!

LET’S MAKE A

RAINBOW!

THINGS YOU WILL NEED!

RULER

A4 SIZE BLACK SHEET

A PAIR OF SCISSORS

PENCILS AND ERASERS

A4 SIZE WHITE SHEET

GLUE BOTTLE

CD (COMPACT DISC)

DID YOU KNOW? PARALLEL LINES

PERPENDICULAR LINES (900 )

In a rectangle, opposite sides are equal in length and are parallel to each other.

In a square, all the sides are equal in length and opposite sides are parallel to each other.

In a right angled triangle, one angle is 900.

A trapezium is a quadrilateral, in which two opposite lines are parallel. While, the two other lines intersect with each other when they are further extended.

10 cm

4 cm 7 cm

3 cm

0.2 cm

1.5 cm

4 cm

0.4 cm

4 cm

4 cm 1.5 cm SLIT B

0.2 cm SLIT A 8 cm

11 cm 1 cm

4 cm

7 cm

3 cm 4 cm

cm 10

LET’S MAKE!

Can you guess the shapes above ?

Use the information given in the page above to help understand this template. Then redraw this template on both, the white and the black A4 sized sheet.

Cut out the template from both the sheets. Also cut out SLIT A and SLIT B from both the sheets. Now, stick both the sheets behind one another and let’s begin making!

Note : This diagram represents the actual size of the template.

FOLLOW THE STEPS

Arrow for outward fold (mountain fold)

Arrow for inward fold (valley fold)

Step 1 : Place the template, such that the black surface is above and the white surface is below.

Fold inside or fold inwards (valley fold)

Fold outside or fold outwards (mountain fold)

Line for cutting

Step 2 : After folding the the two triangles, your structure should look like drawing above.

x

x

z

Step 3 : Fold the two “x” flaps (trapeziums) outwards and the centre square “z” inwards.

Arrow for outward fold (mountain fold)

Arrow for inward fold (valley fold)

Fold inside or fold inwards (valley fold)

Fold outside or fold outwards (mountain fold)

z

Line for cutting

Step 4 : Now fold the two side flaps (trapeziums) around “z” inside and glue them to the inner surface of the triangles

q

Arrow for outward fold (mountain fold)

Step 5 : Fold the rectangle “q� downwards.

Arrow for inward fold (valley fold)

Fold inside or fold inwards (valley fold)

x

Fold outside or fold outwards (mountain fold)

Line for cutting

Step 6 : Stick the flaps of the rectangle onto the outward flaps(x).

4 cm

Step 7 : Cut out a segment of 4 cm length and approximate width to fit into the cavity.

Step 8 : Stick the cut out CD into the hollow area of the of the model. Now your model is ready!

Source of White Light

SLIT A SL

IT

HOW TO LOOK?

This model is called a spectroscope.

Face SLIT A towards a source of white light (tube light or the light from the sun). And look inside the spectroscope through the SLIT B.

B

What do you see?

Why does this happen?

Find out next!

Source of White Light

HOW DOES IT WORK?

Music is recorded as circular marks on the shiny surface of a CD. These marks are so close, they act as diffraction grating for light. This diffraction grating refracts white light into the 7 colours of the rainbow.

The spectroscope is a device which splits white light into the visible spectrum. The visible spectrum is made of electromagnetic waves of light, that can be seen by the human eye.

REFERENCES www.exploratorium.edu. “Science Snacks.”

Accessed April 25, 2018. https://www.exploratorium.edu/snacks/cd-spectroscope. http://www.arvindguptatoys.com. “CD - Spectroscope.”

Accessed April 25, 2018. http://www.arvindguptatoys.com/toys/cdspectroscope.html.