Question

The wavelength of the blue light given off by a mercury vapor street lamp is 457 nm. What is the frequency of this light in hertz (s^ -1 )? pls help

Answer 1

Answer:

6.56×10¹⁴ Hz

Explanation:

From the question given above, the following data were obtained:

Wavelength = 457 nm

Frequency =?

Next, we shall convert 457 nm to metre (m). This can be obtained as follow:

1 nm = 1×10¯⁹ m

Therefore,

457 nm = 457 nm × 1×10¯⁹ m / 1 nm

457 nm = 4.57×10¯⁷ m

Thus, 457 nm is equivalent to 4.57×10¯⁷ m

Finally, we shall determine the frequency of the blue light as follow:

Wavelength = 4.57×10¯⁷ m

Velocity of light = 3×10⁸ m/s

Frequency =?

Velocity = wavelength x frequency

3×10⁸ = 4.57×10¯⁷ × frequency

Divide both side by 4.57×10¯⁷

frequency = 3×10⁸ / 4.57×10¯⁷

frequency = 6.56×10¹⁴ Hz

Therefore, the frequency of the blue light is 6.56×10¹⁴ Hz