35. Standing at a crosswalk, you hear a frequency of 560Hzfrom the siren of an a

Question

35. Standing at a crosswalk, you hear a frequency of 560Hzfrom the siren of an approaching ambulance. After the ambulancepasses, the observed frequency of the siren is 480Hz. Determine theambulances speed from these observations. I need to check my work. Please help. I will rate well asalways. 35. Standing at a crosswalk, you hear a frequency of 560Hzfrom the siren of an approaching ambulance. After the ambulancepasses, the observed frequency of the siren is 480Hz. Determine theambulances speed from these observations. I need to check my work. Please help. I will rate well asalways.

Explanation / Answer

from the formula     v = (v`-u0)*v0/(v`-us) where v`= speed of sound in air u0=speed of observer wrt medium taken positive when itmoves towards the source and taken negative when it moves away fromthe source us=speed of source wrt medium taken positive whenit moves towards the observer and taken negative when it moves awayfrom the observer. v0=original frequency v= apparent frequency so applying this formula,,,,, in first case... 560 = (332)*v0/(332-us)  (u0=0) so,185920-560 us -332v0   .............(1) in other case 480=(332)*v0/(332+us) 159360 + 480 us- 332 v0 ..........(2) solving 1 and 2 we get us=25.538 m/s (ans) speed of source is 25.538 m/s

Related Questions

Navigate

• Browse (All)
• Browse 3
• Subjects

---

---

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