Answer:
Explanation:
Given that,
Ey = 375•Cos[kx - (2.20 × 10¹⁴t)]
Speed of light
c = 3×10^8m/s
What is the wavelength?
Generally,
The wavelength of electromagnetic wave is give as
Ey = Emax•Cos(kx—wt)
k = 2π/λ
w = 2πf
Ey = Emax•Cos(2πx/λ—2πft)
Comparing this to the wave equation given,
We notice that,
2πx/λ = kx
Also,
2.20 × 10¹⁴t = 2πft
t cancels out
2.20 × 10¹⁴ = 2πf
f = 2.20 × 10¹⁴ / 2π
f = 3.5 × 10¹³ Hz
Since we are given that
c = 3×10^8m/s
Then, using relationship between c, v and λ.
c = fλ.
λ. = c/f
λ. = 3×10^8 / 3.5 ×10¹³
λ. = 8.57 × 10^-6m
λ. = 8.57 μm
The wavelength of the electromagnetic wave is 8.57 micro meter (8.57 μm)