As a classroom demonstration of the Doppler effect, a teacher whirl a child\'s t

Question

As a classroom demonstration of the Doppler effect, a teacher whirl a child's toy in a horizontal circle of radius 1.00 meter with a frequency of revolution is 60.0 rpm/ As the toy revolves it makes a whistling sound of frequency 200 Hz.

Determine the maximum and minimum frequencies heard by students who are sitting at some distance from the teacher. Assume that the speed of sound is 340 m/s.

The answers are 204 Hz and 196 Hz. Please show all work, its a college Physics one class so basic formulas please!!

Explanation / Answer

r = 1 m ; w = 60 rpm = 6.28 rad/s ; f' = 200 Hz ; V = 340 m/s

we know that, v = r w = 1 x 6.28 = 6.28 m/s

this is the speed of the toy.

we know from Dopplers effect of sound

f' = [(V + Vo)/(V -/+ Vs)] f

f = f' (V - Vs)/(V + Vo) [ when it moves away we take - and + when it approaches]

f1 = 200 (340 - 6.28)/(340 + 0) = 196 Hz

f2 = 200 (340 + 6.28)/(340 + 0) = 204 Hz

Hence, f1 = 196 Hz and f2 = 204 Hz

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

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