1. Chapter 14/25 Electromagnetic Waves

2. The Electromagnetic Spectrum Electromagnetic SpectrumElectromagnetic Spectrum

3. Figure 25-3 The Right-Hand Rule Applied to an Electromagnetic Wave Electromagnetic WaveElectromagnetic Wave

4. Figure 25-1 All Accelerating Charges Radiate Electromagnetic Waves

5. Receiving Radio Waves - Resonance Resonance

6. Maxwell - Electromagnetic waves All electromagnet waves travel at the speed of light in a vacuum

7. Roses are Red, Violets are Violet 1 nanometer = 10 -9 metersEx: 600 nm = 6.00 x 10 -7 m What is the speed of Light?

8. Speed of Light The speed of light can be defined as the speed it takes light to travel one meter in 1/299,792,458 of a second.The speed of light can be defined as the speed it takes light to travel one meter in 1/299,792,458 of a second. Presently, the speed of light has a fixed value of 299,792,458 m/s. or……..Presently, the speed of light has a fixed value of 299,792,458 m/s. or…….. c = 3.00 × 10 8 m/s; c = f λc = 3.00 × 10 8 m/s; c = f λ c = f λc = f λ Who measured the speed of light?Who measured the speed of light?speed of lightspeed of light

9. c=f λ or v=f λ A cell phone transmits at a frequency of 1.33 x 10 8 Hz. What is the wavelength of the electromagnetic wave used by this phone?A cell phone transmits at a frequency of 1.33 x 10 8 Hz. What is the wavelength of the electromagnetic wave used by this phone? c = f λc = f λ 3.00 × 10 8 m/s = 1.33 x 10 8 Hz (λ)3.00 × 10 8 m/s = 1.33 x 10 8 Hz (λ) λ = 2.26 mλ = 2.26 m

10. Galileo One of the first attempts to measure the speed of light. What do you think he discovered? Conclusion: Light was really fast!!!!

11. Romer: Using the moons of Jupiter to Determine the Speed of Light

12. c=f λ A television is tuned to a station broadcasting at a frequency of 7.30 x 10 7 Hz. For best reception, the rabbit-ear antenna used by the TV should be adjusted to have a tip-to-tip length equal to one-third a wavelength of the broadcast signal. Find the optimum length of the antenna.A television is tuned to a station broadcasting at a frequency of 7.30 x 10 7 Hz. For best reception, the rabbit-ear antenna used by the TV should be adjusted to have a tip-to-tip length equal to one-third a wavelength of the broadcast signal. Find the optimum length of the antenna. c = f λc = f λ 3.00 × 10 8 m/s = 7.30 x 10 7 Hz (λ)3.00 × 10 8 m/s = 7.30 x 10 7 Hz (λ) λ = 4.11 mλ = 4.11 m So, 4.11/3 = 1.37 mSo, 4.11/3 = 1.37 m

13. Speed of Light

14. Albert Michelson Albert Michelson

15. Figure 25-7 Fizeau’s Experiment to Determine the Speed of Light

16. Doppler Radar

17. Microwaves A microwave oven produces electromagetic waves with a wavelength of about 12 cm. What are the frequency of such waves?A microwave oven produces electromagetic waves with a wavelength of about 12 cm. What are the frequency of such waves? c = f λc = f λ 3.00 × 10 8 m/s = (f) 0.12 m3.00 × 10 8 m/s = (f) 0.12 m λ = 2.26 mλ = 2.26 m

18. Doppler: Red Shift / Blue Shift Which part of the Galaxy above will produce a Red Shift and Which part will produce a Blue Shift? Top Blue, Middle Red, Bottom Red