Question Detail
Question
Light travels at a speed of 2.0 × 10^-5 m/s in a glass block. In the glass, the wavelength of the light is 4.0 × 10^-7 m. What is the frequency of the light?
Correct Answer
Option D is the correct answer.
Detailed Explanation
The speed of a wave (v), its frequency (f), and its wavelength (λ) are related by the equation v = fλ. To find frequency, we rearrange: f = v/λ. f = (2.0 × 10^-5 m/s) / (4.0 × 10^-7 m) = 50 Hz. There seems to be a mismatch in the options. The correct calculated value is 50 Hz, but the options are in powers of 10^-15. Rechecking the numbers: The speed is 2.0×10^5 m/s? If v = 2.0×10^-5 m/s, f = 50 Hz. None of the options match. If v = 2.0×10^-5 m/s and λ = 4.0×10^-7 m, f = 50 Hz. There is an error. Let's assume v = 2.0×10^5 m/s. Then f = 5.0×10^11 Hz. Still not matching.
Hint
Use the wave equation: speed = frequency × wavelength (v = fλ). Solve for f.