Conway—On the Reflection of Electric Waves by a Moving Plane Conductor. 97 
Let the incident wave-train be given by 
X = F( Vt + 2) 
1 
B=- ph(Vi+e); 
and assume for the reflected system 
X’ = $(Vt -2), 
B= 7 4 (Vt-2) 
then it is required to determine ¢. 
The boundary condition is 
XX db I? = lh (B |B) 
when z=h, we. 
o[ve—s@]=— LO ave ss). 
V+. 
V—-fi(d) 
By putting Vt—/(t)=€, and eliminating ¢, we get the value $(€). For 
instance, if f(t) = vt where v is a constant, 
V+ /V+uv 
b(€)=— Wow TE aes é), 
indicating a change of amplitude and a Doppler change of period. In certain 
other cases—for instance, in the case of uniform acceleration—we may perform 
the elimination algebraically; but in all cases we can do it graphically. I 
we introduce functions ¢; and /,, such that 
oi (E) = $(€); HY (€) = FE) 
then it will be sufficient to determine ¢, such that 
PL Ve—f)] =— Wives 7). 
