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## Homework Statement

Man travels down the highway in his car whistling middle C

A policeman has a defective radar gun but passed a physics course. He hears the

pitch change from D(294 Hz) immediately above middle C(262Hz) to A#(233Hz) immediately below

middle C as the car passes.

a) How fast is Professor Zoom traveling?

b) Should Professor Zoom get a ticket? if speed limit is 100km/hr

## Homework Equations

f = frequency of source

f1 = frequency at observer

c = speed of sound (330m/s)

v = velocity of observer

v1 = velocity of source

source moving towards stationary observer.

f x c/(c-v1) = f1

source moving away from stationary observer.

f x c/(c + v1) = f1

## The Attempt at a Solution

So for source moving towards stationary observer

f x c/(c-v1) = f1

262(330)/330-v1=294

v1=36m/s

source moving away from stationary observer.

f x c/(c + v1) = f1

262(330)/330+v1=233

v1=41m/s

I just want to know if im on the right track, or what am I doing wrong? and do i add those two velocity together? when you convert those velocities into km/h they surpass 100km/hr so I said that yes he does get a ticket. Help please :) im a little lost...