Question

Red lights on a traffic light have a frequency of 4.3 X 10^15 Hz. What is the red light’s wavelength in meters? (Speed of light (c)= 3.00 X 10^8 m/s)
A. 1.5 X 10^-49 meters

B. 7.0 X 10^-8 meters

C. 1.4 X 10^7 meters

D. 1.3 X 10^24 meters

Answer 1

Answer:

The correct answer to this problem is B. 7.0 X 10^-8 meters

Explanation:

To solve this problem, we have to use the following equation:

c = λν, or speed of light = wavelength*frequency

If we substitute in the values we are given by the problem, we get:

3.00 * 10^8 m/s = (4.3 * 10^15 Hz)*(wavelength)

wavelength = 6.98 * 10^-8 m

Since the given value has 2 significant figures, our answer should similarly include two significant figures since the operation in the problem was multiplication.

Therefore, the answer is B. 7.0 X 10^-8 meters.

Hope this helps!