How Light Travels

How Light Travels

Mark Bryan M. Aguinaldo

Teacher III​

Most Essential Learning Competency (MELC):

Describe how light travels. S4FE-IIIf-g-4

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Learning Objectives:

1. Describe how light travels.

2. Infer that light travels in a straight line.

3. Explain the behavior of light as it strikes different kinds of surfaces.

Multiple Choice

Which of the following materials transmit all light that strike it?

• clear water

• wax paper

• frosted windows

• wood

Multiple Choice

How does light travel? Light travels in a ___ path.

• curve

• wavy

• straight

• zigzag

Multiple Choice

Wax paper or a foggy window is an example of what type of material?

• opaque

• translucent

• transitional

• transparent

Multiple Choice

What do you call material that absorbs most of all the light that strikes it, making objects NOT visible?

• opaque

• translucent

• transitional

• transparent

Multiple Choice

Which images are opaque?

• A & C

• A & E

• E & F

• E & F

Lesson 1: How Light Travels

Can you imagine our world without light? Without light, everything will be in darkness. You will not be able to see the objects in the classroom like tables, chairs, and books. You will not be able to see the mountains and trees. Plants will not grow and produce food. Life would be impossible.

Light is a form of energy that makes all life processes possible. The sun is the greatest source of energy. It is a radiant energy that provides us with light and heat. Light from the sun travels to the Earth and enables us to see things. How does light travel?​

​ Have you ever wondered why the sky is blue and the sunset appears to be red sometimes? Or maybe you noticed that sometimes the moon appears to be red or the sunset is orange. The sun is responsible for all these things. The sun produces light. Light is the natural energy produced to make things able to be seen. Let us learn more about light and what it is.

Light is made of electromagnetic radiation and always follows a straight path. Visible light is the type of light that humans can see, but there are also other types of light that we cannot see, such as ultraviolet and infrared light.

Our human eyes are not able to see these types of light because the frequency, or the speed the light moves at, is undetected by human eyes. Interestingly though, some insects are able to see infrared light.

Light travels very fast! So fast that people will never be able to move as fast as light. Some scientists believe that if humans were able to travel as fast as light can, you could travel through time! Imagine being able to go to the past to see dinosaurs or even going to the future!​

Transmission of Light

Light behaves differently when it strikes different surfaces. When light strikes a surface, it may be absorbed, transmitted, or scattered.

Light is transmitted when the surface of an object allows it to pass through. Depending on how much light pass through, a material may be classified as transparent, translucent, or opaque.​

Transparent materials transmit all light that strike it. Examples of transparent materials are clear water, clear gas, and air.

Translucent materials transmit some light and scatter the rest. The image of an object cannot be seen clearly in translucent materials, such as lampshades, wax paper, and frosted materials on windows.

Opaque materials do not transmit light at all. An opaque material absorbs most of the light that strikes it. Examples of opaque materials are a cement wall, wood and a thick curtain cloth.

​Formation of Shadow

Light rays can be blocked. If we try to block light rays, a shadow is formed. A shadow is the dark area formed when straight light rays are formed when straight light rays are blocked. Shadows are usually formed when an opaque object or material is placed in the path of rays of light. The opaque material does not let the light pass through it.

LET'S CHECK YOUR UNDERSTANDING!

Multiple Choice

Which of the following materials transmit all light that strike it?

• clear water

• wax paper

• frosted windows

• wood

Multiple Choice

How does light travel? Light travels in a ___ path.

• curve

• wavy

• straight

• zigzag

Multiple Choice

Wax paper or a foggy window is an example of what type of material?

• opaque

• translucent

• transitional

• transparent

Multiple Choice

What do you call material that absorbs most of all the light that strikes it, making objects NOT visible?

• opaque

• translucent

• transitional

• transparent

Multiple Choice

Which images are opaque?

• A & C

• A & E

• E & F

• E & F

Multiple Choice

Which of the following statements is true about light?

• Light behaves the same when it strikes different materials

• .Light is produced by all visible objects.

• Shadow is formed when it strikes a transparent material.

• When light strikes a surface, it may be absorbed, transmitted, or scattered.

Multiple Choice

What happens to the shadow when an object moves closer to its light source? The shadow gets__________.

• bigger

• gets smaller

• changes shape

• stays the same

Multiple Choice

Which material would be the best choice if you want to allow some light, but would also like some privacy?

• opaque

• translucent

• rotational

• transparent

Multiple Choice

What do you call material that allows light to pass through, making objects clearly visible when viewed through this material?

• opaque

• translucent

• rotational

• transparent

Multiple Choice

What is formed when object blocks the path of light?

• fog

• reflection

• problem

• shadow