Notifications
Clear all
0
28/12/2021 3:01 pm
Topic starter
A source A produces frequency of horn 1120 Hz. Source and observer are moving towards each other with speeds of 36 km/hr and 72 km/hr respectively. Find frequency of horn observed by the observer (speed of sound V = 330 m/s).
(a) 1210 Hz
(b) 1200 Hz
(c) 1225 Hz
(d) 1250 Hz
1 Answer
0
28/12/2021 3:06 pm
Correct answer: (c) 1225 Hz
Explanation:
Vs = 36 km/hr
= 10 m/s
V0 = 72 km/hr
= 20 m/s
f′ = \(f_0\Big(\frac{V+V_0}{V-V_s}\Big)\)
f′ = 1120\(\Big[\frac{330+21}{330-10}\Big]\)
= 1120 ×\(\frac{35}{32}\) = 1225 Hz
This post was modified 3 years ago by Reyana09