Hello all steemians and science lover. Now i want to share the experiment that ever we learned it at School when we were student. This experiment aims knowing and understanding the properties of light and understanding the nature of light creeps straight, penetrates the clear object and can be reflected.

Source

Theoretical basis

A. Properties of Light

1. Light Passing Straight

The light emitted by a light source travels in all directions. If the medium is homogeneous, then light is straight. Evidence of light creeping straight in the beam of sunlight that penetrates into the dark room.

2. Light can be reflected

Reflection of light there are two types of reflection diffuse (diffuse reflection) and regular reflection. The diffuse reflection is a reflection that occurs when light is on a rough or uneven surface. In this reflection, the irradiance rays are irregular. While regular reflections occur when the light on the surface of a smooth, flat, and shiny, such as a mirror. The reflected rays have a regular direction.

Based on the shape of the mirror surface is divided into three kinds of flat mirror, convex mirror, and concave mirror.

3. Light Able to penetrate Object

Events passing through the light in the clear can be seen when looking at a clear plastic, glass, or other clear objects in the direction of the light. The rays can be seen because light can penetrate the clear object. If the light of dark matter (not clear) such as trees, hands, cars, it will form a shadow.

4. Light Can be Described

The decomposition of light (dispersion) is the decomposition of white light into light that has a variety of colors. An example of a rainbow, which occurs as a result of the sunlight described by raindrops.

5. Refractible Light

The event of splitting the direction of light propagation after passing through a different propagation medium is called refraction.
If light comes from less dense substances to more dense substances the light will be biased toward the normal line. For example light from air to water.

Conversely, if light comes from a denser substance to a less dense substance, then light will be refracted away from the normal line. For example light from water to air. Examples of refraction of light that is pencil is inserted into the water will look bent, the bottom of the pond looks shallow.

Tools and materials

Tools and materials used in this lab include:

1. Thick paper / Aqua carton 2. Plaster 3. Candles 1 piece 4. Matches 5. Scissors 6. Flat mirror 7. Flashlight / Laser 8. Large plastic bags 9. Camera

Ways of working

1. Prepare tools and materials (cardboard, scissors, masking tape).
2. Cut a 15 x 20 cm cardboard box for 3 pieces and measure 15 x 40 cm for 1 piece.
3. Give 1 hole in ¼ part to 3 carton before, take center position.
4. Complete the material as shown below:
   
5. After the material is assembled place a candle that burns on the front.
6. Observe the candle from the front of the hole and draw the conclusion.
7. Prepare tools and materials in the form (candles, flashlights / lasers and plastics).
8. Clear plastic sheeting on top of the burning candle, observe then give the lighting from top to bottom the plastic then observe and conclude.
9. Prepare tools and materials in the form of a flat mirror.
10. Put the mirror on the table alone.
11. Give lighting then observe what happens.

Results Observation / Work Results

Based on the observation that the light properties such as light can propagate straight, penetrate the clear and can bounce, which can be seen in the picture below:

Discussion

From the results of the first observation shows that the light of a candle / flashlight from the front of a cardboard circuit that has been given a parallel hole of light can propagate straight.

From the second observation indicates that the light of a candle / flashlight passing through the transparent body can be seen whereas on the contrary in a non-clear body like a light box can not penetrate. So it can be concluded that light can penetrate a clear object.

From the third observation it appears that the flashlight that is directed to a flat mirror can bounce off.

Conclusion

Based on the first observation it is evident that the light of the candle / flashlight from the front of the cardboard circuit that has been given a parallel hole of light can propagate straight.

Based on the second observation when the light of a candle / flashlight passing through the clear object can be seen whereas on the contrary on a non-clear object such as a light box can not penetrate. So it can be concluded that light can penetrate a clear object.
Based on the results of the third observation it is evident that a flashlight directed by a flat mirror can bounce off.

So it is evident that the light properties of which can propagate straight, can penetrate the clear and can bounce.

Sources :

The Nature Of Light

The basic nature of light

Particle nature of light

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