Question

1. your phone is dead so you turn on the radio in the car. the dj announces that the frequency of the station youre turning into is sunny 107.9 fm (f = 107.9 x 10° hz). how fast (what speed) is the next song traveling to your car stereo from the station? a. 3.24 x 10° m/s c. 3.00 x 10° m/s b. 3.60 x 10° m/s d. 2.78 m/s 18. consider the following two electromagnetic waves. select the one statement that is true about these two waves: wave 1 wave 2 a. wave 1 has a higher frequency and lower energy than wave 2. b. wave 1 has a longer wavelength than wave 2. c. wave 2 has a lower frequency and longer wavelength than wave 1. d. wave 2 travels at a slower speed than wave 1. 19. use this image of the electromagnetic spectrum to answer questions #19 - 22 which color of visible light has the shortest wavelength? a. red c. blue b. green d. violet 20. which color of visible light has the lowest energy? a. red c. blue b. green d. violet 21. which one of the following statements is false? a. infrared radiation has more energy than x - rays. b. gamma radiation has the most energy of all electromagnetic waves. c. radio waves have the longest wavelengths of the electromagnetic spectrum. d. violet light has the highest energy of the visible light portion of the em spectrum. 22. which one of the following statements is true? a. radio waves travel the slowest of all em waves because theyre so long. b. yellow light has higher energy photons than red light. c. x - rays have longer wavelengths than all visible light. d. infrared waves have more energy than ultraviolet waves because theyre hotter.

Explanation:

Question 17

Step1: Recall the speed of electromagnetic waves

All electromagnetic waves (including radio waves) travel at the speed of light in a vacuum, \(c = 3.00\times10^{8}\text{ m/s}\).

Step1: Analyze wave properties relationships

The energy of a wave \(E = h
u\) (where \(h\) is Planck's constant and \(
u\) is frequency), and \(c=\lambda
u\) (where \(c\) is the speed of light, \(\lambda\) is wavelength). For electromagnetic waves in a vacuum, speed \(c\) is constant.
If wave 1 has a shorter wavelength (\(\lambda\)) than wave 2 (from the drawn waves, wave 1 has more oscillations in a given length, so \(\lambda_1<\lambda_2\)), then from \(c = \lambda
u\), \(
u=\frac{c}{\lambda}\), so \(
u_1>
u_2\). And from \(E = h
u\), \(E_1>E_2\).

• Option a: Incorrect, since \(E_1>E_2\)
• Option b: Incorrect, \(\lambda_1<\lambda_2\)
• Option c: Correct, since \(

u_1>
u_2\) (so \(
u_2 <
u_1\)) and \(\lambda_2>\lambda_1\)

• Option d: Incorrect, all electromagnetic waves in a vacuum travel at speed \(c\)

Step1: Use the electromagnetic - spectrum relationship

From the electromagnetic spectrum, as we move from red to violet in the visible spectrum, the wavelength decreases. The order of wavelengths (from longest to shortest) in the visible spectrum is red > orange> yellow > green> blue> indigo > violet.

Answer:

c. \(3.00\times 10^{8}\text{ m/s}\)

Question 18