You\'ve been hired as a consultant to the police department to design a new devi

Question

You've been hired as a consultant to the police department to design a new device that measures the speed of vehicles. The idea is to make a small, rugged device to be placed in the road that will pick out a specific frequency emitted by the car as it approaches and then measure the frequency as it recedes. The device will then use this data to calculate the speed of the car. You are currently in the process of writing a program for the chip in your new device. To complete the program, you need a formula that determines the speed of the car using the measured frequencies. You may also include in your formula any physical constants that you might need.

Explanation / Answer

If the observer and source are approaching each other the frequency heard by the observer (f') is
f'=f(v+vo)/(v-vs)
If they are receding (moving away from each other)
f'=f(v-vo/v+vs)

v=speed of wave
vo=speed of observer
vs=speed of source
f=frequency at source
f'=frequency observed by observer.

Related Questions

Navigate

• Browse (All)
• Browse Y
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.