Presentation on theme: "Section 2 The Nature of Light Notebook # 6. 1.Visible light is composed of waves that have several different wavelengths. What happens to light that passes."— Presentation transcript:
1.Visible light is composed of waves that have several different wavelengths. What happens to light that passes through a prism? 2.Why do we see rainbows on rainy days? 3.An airplane can be detected by radar. When radio waves strike an airplane, they are reflected back to a detector and the airplane shows up on a radar screen. Explain how stealth airplanes fly through the air without being detected by radar. Bellringer: Section 2
I. Waves and Particles A.Light –a transverse wave that does not need a medium. 1. Light is also electromagnetic waves. B. Light – a packet of energy. 1. called a photon. C. Both models are acceptable to scientists.
D. Frequency & energy are proportional. 1. As frequency increases, so does energy. E. Speed of light depends on: 1. The medium in which it is traveling. i.Fastest in a vacuum. ii. c = 3.0 x 10 8 m/s
II. The Electromagnetic Spectrum A.Electromagnetic waves A.Electromagnetic waves – waves created by vibrating electric charges. 1.Electromagnetic waves are made when an electric charge moves back and forth. 2. When an electric charge vibrates, the electric field around it vibrates. 3. This also causes the magnetic field to vibrate.
B. The range of electromagnetic wave frequencies is known as the Electromagnetic Spectrum
Radio waves MicrowavesInfraredOptical Ultraviolet X-Rays Gamma rays Low to high Frequency Long to short C. Radio Waves - long, low frequency. Low photon energy. 1.Used in communications and cordless telephones.
D. Microwaves - used in cooking food and communications (cell phone signals) E. Infrared radiation - generally associated with heat. 1.Used to keep food warm & produce heat images.
F. Visible Radiation - only part we can see. G. Ultraviolet Radiation – used in hospitals to kill bacteria.