RELATIVITY:

CONCEPT AND SCENARIOS

PREPARED BY: MICHAEL VINCENT M. ECLEVIA

By now we understand that Physics is concerned with the motion of objects, and the quantitative analysis of motion.

But this can be tricky if you consider that everything is in a constant motion.

In this lesson, students are expected to:

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• Define relativity; (STEM_GP12OPT-IVg-37)
• Explain Galilean Relativity; (STEM_GP12OPT-IVg-38)
• State the postulates of Special Relativity and their consequences; (STEM_GP12OPT-IVg-39)
• Apply the time dilation and length contraction formulae; (STEM_GP12OPT-IVg-40)
• Apply the relativistic velocity addition formula. (STEM_GP12OPT-IVg-40)

Learning Objectives

Directions: Read the questions carefully and analyze the pictures on the screen. Try to apply the concepts about light from our previous lesson. Work with your group and answer the following question.

ELICIT: TOGETHER AS ONE!

1. Light can propagate in two different ways. What are the two natures of light?

Directions: Read the questions carefully and analyze the pictures on the screen. Try to apply the concepts about light from our previous lesson. Work with your group and answer the following question.

GROUP REVIEW!

1. Light can propagate in two different ways. What are the two natures of light?

Wave and Particles

REVIEW!

2. We can determine the purity of a diamond using total internal reflection. The brilliance produced by the diamond is due to its high index of refraction. What is the index of refraction of diamonds?

Directions: Read the questions carefully and analyze the pictures on the screen. Try to apply the concepts about light from our previous lesson. Work with your group and answer the following question.

REVIEW!

2. We can determine the purity of a diamond using total internal reflection. The brilliance produced by the diamond is due to its high index of refraction. What is the index of refraction of diamonds?

n = 2.417

Directions: Read the questions carefully and analyze the pictures on the screen. Try to apply the concepts about light from our previous lesson. Work with your group and answer the following question.

REVIEW!

3. White light can deviate into seven different colors using a prism. Those are the visible colors we see in a rainbow, what is the wavelength of visible light?

Directions: Read the questions carefully and analyze the pictures on the screen. Try to apply the concepts about light from our previous lesson. Work with your group and answer the following question.

REVIEW!

3. White light can deviate into seven different colors using a prism. Those are the visible colors we see in a rainbow, what is the wavelength of visible light?

400 nm – 700 nm

Directions: Read the questions carefully and analyze the pictures on the screen. Try to apply the concepts about light from our previous lesson. Work with your group and answer the following question.

REVIEW!

4. Sunlight is our source of vitamin D which is good for our health, but our eyes beg to differ. Staring too long may cause our eyes to squint or irritate, why it is hard to maintain eye contact with Sun?

Directions: Read the questions carefully and analyze the pictures on the screen. Try to apply the concepts about light from our previous lesson. Work with your group and answer the following question.

REVIEW!

4. Sunlight is our source of vitamin D which is good for our health, but our eyes beg to differ. Staring too long may cause our eyes to squint or irritate, why it is hard to maintain eye contact with Sun?

It produces unpolarized light in all directions.

Directions: Read the questions carefully and analyze the pictures on the screen. Try to apply the concepts about light from our previous lesson. Work with your group and answer the following question.

Directions: Read the questions carefully and analyze the pictures on the screen. Try to apply the concepts about light from our previous lesson.

REVIEW!

5. Convex mirrors are usually used for surveillance cameras and car side mirrors. What is the nature of the image that usually appears in a convex mirror?

Directions: Read the questions carefully and analyze the pictures on the screen. Try to apply the concepts about light from our previous lesson.

REVIEW!

5. Convex mirrors are usually used for surveillance cameras and car side mirrors. What is the nature of the image that usually appears in a convex mirror?

Virtual, Erect and Reduced

ENGAGE: MOTIVATION

What do you see in this picture?

Who do you think is correct?

Note: There are three understanding about relativity.

What is relativity?

Relativity, fundamentally, is the study of how different observers view the same reality.

Note: There are three understanding about relativity.

Note: There are three understanding about relativity.

The bird is slow.

The bird is fast.

Two person will give different accounts of the same event.

Which observer is correct?

Note: There are three understanding about relativity.

The bird is slow.

The bird is fast.

Two person will give different accounts of the same event.

Which observer is correct?

Note: There are three understanding about relativity.

The bird is slow.

The bird is fast.

We need to understand why their observations are different hence the study of relativity.

Both are correct.

Note: There are three understandings about relativity.

There are three understandings of Relativity:

Galilean Relativity

Special Relativity

General Relativity

Any questions?