2 In SI units, the electric field in an electromagnetic wave is described by
4 E_y = 100\sin(1.00\E{7}x - \omega t)
6 Find \Part{a} the amplitude of the corresponding magnetic field
7 oscillations, \Part{b} the wavelength $\lambda$, and \Part{c} the
9 \end{problem*} % problem 24.8
13 The amplitude is the magnitude of the oscillation, which just comes
14 from the prefactor outside the trig function. In this case,
18 By comparing with the standard form of sinusoidal waves
20 Y = A \sin(kx - \omega t) \;,
22 we see that the wavenumber $k=1.00\E{7}\U{rad/m}$. Converting radians
23 to cycles and inverting yields
25 \lambda = \frac{2\pi\U{rad/cycle}}{k} = 628\U{nm/cycle}
29 Once we know the length of a cycle, and how fast the wave is moving, we can find out how many of them occur in a second
31 f = \frac{c}{\lambda} = \frac{3.00\U{m/s}}{628\U{nm/cycle}}
32 = 477\E{12}\U{cycles/s} = \ans{477\U{THz}}