Physics of The Very Smal S2, 2015 Problem Solving Task 4 Optics Exercise 35.3: E
ID: 1365928 • Letter: P
Question
Physics of The Very Smal S2, 2015 Problem Solving Task 4 Optics Exercise 35.3: Engineering Exercise 35.3: Engineering A radio transmitting station operating at a frequency of 125 MHz as two identical antennas that radiate in phase. Antenna Bis 8.95 m to the right of antenna A. Consider point P between the antennas and along the line connecting them, a horizontal distance r to the right of antenna A. session masteringphysics.com Part A For what values of a will constructive interference occur at point P? Enter your answers in ascending order separated by a comma AEG Submit My Answers Give Up Signed in as n9375104 ALKHALDY Help Close Resources previous l 4 of 10 I next Provide Feedback ContinueExplanation / Answer
for constructive interference, the path difference should be integer multiple of wavelength.
here speed of the wave=3*10^8 m/s
frequency=125*10^6 Hz
then wavelength=speed of the wave/frequency of the wave=2.4 m
distance of point P from A=x
then distance of point P from B=8.95-x
then path difference=8.95-x-x=8.95-2*x
so for constructive interference,
8.95-2*x=n*2.4
where n=0,1,-1,2,-2,...etc
n=0
==>2*x=8.95
==>x=8.95/2=4.475 m
for n=1:
8.95-2*x=2.4
==>x=(8.95-2.4)/2=3.275 m
for n=-1:
8.95-2*x=-2.4
==>x=(8.95+2.4)/2=5.675 m
for n=2:
8.95-2*x=2*2.4
==>x=(8.95-2*2.4)/2=2.075 m
for n=-2:
8.95-2*x=-2*2.4
==>x=6.875 m
for n=3:
8.95-2*x=3*2.4
==>x=0.875 m
for n=-3 m:
8.95-2*x=-3*2.4
==>x=8.075 m
for n=4, there is no positive solution for x.
hence answers are:
0.875 m, 2.075 m, 3.275 m, 4.475 m, 5.675 m, 6.875 m. 8.075 m