Question

The distance from Earth to the sun is 1.5×10^8km

Find the number of crests in a light wave with a frequency of
1.0×1014 s−1 traveling from the sun to Earth

Answer 1

To find the number of crests in a light wave with a frequency of 1.0×10^14 s−1 traveling from the sun to Earth, we can use the equation v = λf, where v is the velocity of light, λ is the wavelength, and f is the frequency. The distance from the Sun to Earth is given as 1.5 × 10^8 km. To find the number of crests, we can divide the distance by the wavelength: n = (1.5 × 10^8 km) / (2.99792 × 10^−6 km) = 5.002 × 10^13 crests.

Step-by-step explanation:

To find the number of crests in a light wave with a frequency of 1.0×10^14 s−1 traveling from the sun to Earth, we can use the equation v = λf, where v is the velocity of light, λ is the wavelength, and f is the frequency. The velocity of light is approximately 299,792 km/s. We can rearrange the equation to solve for the wavelength: λ = v/f. Plugging in the values, we get λ = 299,792 km/s / 1.0×10^14 s−1 = 2.99792 × 10^−6 km.

The distance from the Sun to Earth is given as 1.5 × 10^8 km. To find the number of crests, we can divide the distance by the wavelength: n = (1.5 × 10^8 km) / (2.99792 × 10^−6 km) = 5.002 × 10^13 crests.

Answer 2

To find the number of crests in a light wave with a frequency of 1.0×1014 s−1, we multiply the frequency by the time light takes to travel the given distance from the sun to Earth, resulting in 5.0×1016 crests.

Step-by-step explanation:

To calculate the number of crests in a light wave from the sun to Earth with a given frequency, we first need the speed of light which is approximately 299,792 km/s (rounded to 299,338 km/s as provided in your reference text). The distance from Earth to the sun is given as about 1.5×108km, and the frequency of the light wave is 1.0×1014 s−1.

First, we find the time it takes for light to travel this distance:

Time = Distance / Speed of light

Time = (1.5×108 km) / (299,338 km/s) = 500 seconds

Next, to find the number of crests, which is equivalent to the number of cycles or waves that pass a point in a given period, we use the frequency:

Number of crests = Frequency × Time = (1.0×1014 s−1) × (500 s) = 5.0×1016

Therefore, the number of crests in a light wave traveling from the sun to Earth with the given frequency is 5.0×1016 crests.