Third Grading Module 4 Light

Module 4: LIGHT WAVES

ARCHIE A. DURAN

what is light???responsible for the sense of sight.

light is a transverse and electromagnetic wave.

travels in a straight path.

first to study lightSir Isaac NewtonChristian HuygensMax PlanckJames Clerk Maxwell

Sir Isaac Newton

he believed that light behaves like a particle.

Christian Huygens

he believed that light behaves like a wave.

Max Planckcame up with what is now known as the Dual-Nature of Light.

Max PlanckHe explained that light can be a particle and can also be a wave.

James Clerk Maxwell

he proposed the electromagnetic theory of light.

James Clerk MaxwellHe combined the concepts of light, electricity and magnetism to come up with his theory forming electromagnetic waves.

Sources of LightNatural sources – like the sunArtificial sources – like bulbs, lamps, candles

***luminous body – an object capable of producing its own light.

energy to lightmany forms of energy transformation can produce light.

ex. in oil lamps (chemical -> light)in fluorescent bulb (electricity -> light)

brightnessdepends on the source and distance from the source.

it also depends from person to person (qualitative)

it can be computed (quantitative)

Candela (cd)is the unit used to express the brightness of an object capable of producing light.

Electromagnetic Spectrum

is the arrangement of electromagnetic waves according to frequency

White Lightthe visible part of the electromagnetic spectrum that can be seen by the human eye.

also known as visible light.

Wavelength

ROYGBIVred has the longest wavelength but lowest frequency.

violet has the shortest wavelength but highest frequency

ROYGBIVred has the lowest energy

violet has the highest energy

energy, frequency, wavelength

frequency = energy frequency = energy wavelength = frequency wavelength = frequency

Health IssuesUV rays are highly energetic than other spectral regions on its left. This could be a possible reason why we are not advised to stay under the sun after 9:00 in the morning.

Prolong use of mobile phones may cause ear infection. This may be due to a higher energy emitted by microwaves used in cellular phones than radio waves commonly used in other communication devices.

Prisma material that splits light into its different colors.

used by Sir Isaac Newton

Dispersionis a phenomenon in which a prism separates white light into its component colors.

Color Spectrum

WHY???

MENTAL EXERCISE

1. What part of the human body can perceive light?

2. Sir Isaac Newton believed that light behaves like a _______.

3. __________ proposed the dual nature of light.

4. In oil lamps, light is produced through the conversion of _______ energy to light energy.

5. An object that has the ability to produce light.

6. Unit used to express luminous intensity.

7. Light wave does not need a medium to travel and thus classified as _____.

8. An object that splits light into its different colors.

9. The different colors of light is known as _p_c_ru_.

10. Which color of light has the longest wavelength and carries lesser energy?