Download to read offline
More Related Content
Similar to LIGHT WAVES from QUIPPER PHYSICS GRADE 7
LIGHT WAVES from QUIPPER PHYSICS GRADE 7
- 1. Lesson 9.5 Visible lightand Electromagnetic Spectrum
- 2. Learning Objectives At theend of this lesson, the learner should be able to do the following: ● Identify the characteristics of light: energy, frequency, and wavelength. ● Relate the characteristics of light such as color and intensity to frequency and wavelength.
- 3. Learn about It •Different theories were proposed to describe the behavior of light. • Newton believed that light behaves like a particle. • Christiaan Huygens proposed that light behaves like a wave. The Nature of Light
- 4. Learn about It •Max Planck proposed a theory known as dual- nature of light. • Light behaves both as a wave and as a particle. The Nature of Light Light behaves both as a wave and as a particle.
- 5. Learn about It •Light travels in a straight path. Light travels the fastest in vacuum. • 299,792,458 meters per second • Shadows are formed when an object blocks the path of light. Characteristics of Light Shadow is formed when an opaque object blocks the beam of light.
- 6. Learn about It Itcontains the range of electromagnetic waves. Electromagnetic Spectrum The electromagnetic spectrum shows the wavelengths and frequencies of different electromagnetic waves.
- 7. Learn about It Wavelengthis the distance between two wave crests, and it will be the same for troughs and the frequency is the number of vibrations that pass over a given spot in one second, and it is measured in cycles per second (Hz) (Hertz).
- 8. Learn about It Theelectromagnetic region arranges electromagnetic waves from lowest to highest frequency. Read My Instructions Visible Under X-ray Glasses
- 9. Learn about It Wavelengthand frequency have an inverse relationship. Thus, increasing the wavelength would lead to a decrease in frequency.
- 10. Learn about It •It has the lowest frequency but has the highest wavelength. • It carries the least energy among all other electromagnetic waves. Radio wave Radio waves are used by broadcasting companies to transmit signals to television or radio networks
- 11. Learn about It •It is used in transmitting or receiving signals in cellular phones. • It is used in cooking or heating food through microwave ovens. Microwave Microwaves are used in microwave ovens for cooking and heating food.
- 12. Learn about It •It occurs at frequencies above those of microwaves and just below the red visible light. • It is used in remote controls. Infrared The remote control uses infrared light to control your television from a distance.
- 13. Learn about It Thevisible light region is a part of the electromagnetic spectrum that can be detected by the human eye. It is composed of six different colors corresponding to different wavelengths. Visible light
- 14. Key Points ● Ifyou combine all the colors of light, the product will be white light. ● Violet light has the shortest wavelength but the highest frequency in the visible spectrum, while red light has the longest wavelength and lowest frequency.
- 15. Learn about It •Ultraviolet rays are commonly emitted by the sun. • They have shorter wavelengths than violet light. Hence, UV rays have a higher frequency. Ultraviolet The rays coming from the sun are considered ultraviolet rays.
- 16. Learn about It Theyare used in clinics, laboratories, or hospitals to check a patient’s bones for breaks or fractures by producing images of bones in a radiographic film. X-rays
- 17. Learn about It •These rays fall in the range of electromagnetic spectrum above soft X-rays and almost in the range of hard X-rays. • Due to its high energy, it can also damage and kill cells. On the other hand, it can be used to treat cancers. • It has the highest frequency but has lowest wavelength. Gamma rays
- 18. Key Points ● Lighthas dual-nature. It can behave as a wave and as a particle. ● Light travels the fastest in vacuum. It also travels in a straight line. ● Visible light is the part of the electromagnetic spectrum that can be seen by human eyes. ● The brightness of light is called intensity which is dependent on the source and distance from the source.
- 19. Check Your Understanding Readand analyze the following statements given. Tell whether the statement is TRUE or FALSE. 1. In the visible light spectrum, red has the longest wavelength. 2. In the visible light spectrum, violet has the highest frequency. 3. If a wave in a spectrum has the shortest wavelength, then it has the lowest frequency.
- 20. Check Your Understanding Readand analyze the following statements given. Tell whether the statement is TRUE or FALSE. 4. The frequency of a wave is directly proportional to its wavelength. 5. The energy of the wave does not depend on the wavelength and frequency.
- 21. Check Your Understanding INTERESTSABILITIES PEOPLE WHO CAN HELP YOU DEVELOP YOUR INTERESTRS AND ABILITIES Example: 1. Music 1. Good in writing Music – my uncle who is good at singing Writing ability – my English teacher 2. 3. 4. 5