find v for a 700.nm wavelength?

Question

i don't need the answer i just need to know how to solve the problem

all i know is wavelength = (3.00 x 10*8m/s) / v
v= frequency
10*8 = 10 to the 8th

Answer 1

Just remember that frequency, velocity, and wavelength are related:

λ = v/f
where λ = wavelength

3.00 x 10*8m/s is the speed of light, so I'm assuming that you're looking for the frequency of light at that wavelength:

Step 1: Rewrite the equation to solve for frequency:
λ = v/f
f * λ / λ = v/f * f / λ
f = v/λ

Step 2: Plug in numbers:
f = 3.00 x 10*8m/s / 7 * 10-7 m