Final answer:
To find the number of crests in the light wave as it travels from the Sun to Earth, we use the equation v = λf. Substituting the given values, we find that the wavelength of the light wave is approximately 3x10^3 km. Dividing the distance from the Sun to Earth by the wavelength, we find that there are approximately 5x10^4 crests in the light wave.
Step-by-step explanation:
The frequency of a light wave is given as 1.0x10^14 s^-1. To find the number of crests in the light wave as it travels from the Sun to Earth, we need to use the equation v = λf, where v is the speed of light, λ is the wavelength, and f is the frequency.
Since the speed of light is a constant and the distance from the Sun to Earth is given as 1.5x10^8 km, we can calculate the wavelength of the light wave using the formula λ = v/f.
Substituting the values, the wavelength is approximately 3x10^3 km.
Now we can find the number of crests in the light wave by dividing the distance from the Sun to Earth by the wavelength of the light wave. This gives us a total of approximately 5x10^4 crests.