CLASS EXERCISE #16 - BASTILLE DAY
(a) What is the direction of the magnetic field of the wave at that point at that
time?
Using the right-hand rule with t- north and It up, the magnetic field must be in the
east direction.
(b) What is the wavelength of this wave?
- œ -Î0 œ Ð3.00 ‚ 108 m/sÑÎÐ5.0 ‚ 1014 HzÑ œ 0.60 ‚ 106 m
or 0.60 .m or 6.0 ‚ 107 m.
(c) Determine the period of this wave.
X œ 1Î0 œ 1ÎÐ5.0 ‚ 1014 HzÑ œ 0.20 ‚ 1014 s œ 2.0 ‚ 1015 s
(d) How much time elapses between when the electric field is a maximum in
the up (  ) direction and the next time it is a maximum in the up (  )
direction?
From a maximum in one direction to a maximum in the other direction is one
period, or X œ 2.0 ‚ 1015 s.
(e) How much time elapses between when the magnetic field is a maximum in
one direction and the next time it is a maximum in the opposite direction?
From a maximum in one direction to a maximum in the other direction is half a
period, or X Î2 œ 1.0 ‚ 1015 s.