A sounding body emitting a frequency of `150 H_(Z)` is dropped from a height. During its fall under gravity it crosses a balloon moving upwards with a constant velocity of `2 m//s` one second after it started to fall . The difference in the frequency observer by the man in balloon just before and just afer crossing the body will be (velocity of sound `= 300 m//s`, `g = 10 m//s^(2))`
A
12
B
6
C
8
D
4
Text Solution
Verified by Experts
The correct Answer is:
A
`f=f_(0)((vpmv_(0))/(vpmv_(s)))` When approaching `f_(a)=150[(300+2)/(300-10)]` when receding `f_(r)=150[(300-2)/(300+10)]rArr f_(a)-f_(r)~=12` hence (A)
Topper's Solved these Questions
SOUND WAVES
RESONANCE|Exercise Solved Examples|24 Videos
SOUND WAVES
RESONANCE|Exercise Board Level Exercise|33 Videos
SIMPLE HARMONIC MOTION
RESONANCE|Exercise Exercise|28 Videos
STRING WAVES
RESONANCE|Exercise Exercise|32 Videos
Similar Questions
Explore conceptually related problems
A body is just dropped from a height. What is its initial velocity?
A packet is dropped from a balloon which is going upwards with the velocity 12m//s . The velocity of the packet after 2 seconds will be
If a source of frequency n moving with velocity v crosses a stationary observer, then the change in the frequency of sound heard by the observer will be (velocity of sound = V)
A balloon is going upwards with a constant velocity 15 m//s . When the ballooon is at 50 m height, a stone is dropped outside from the balloon. How long will stone take to reach at the ground? ("take " g=10 m//s^(2))
A body is dropped from a balloon moving up with a velocity of 4 m//s , when the balloon is at a height of 120 m from the ground. The height of the body after 5 s from the ground is:
At t = 0 source starts falling under gravity and a detector is projected upwards with a velocity 10m/s. For the vertical upward motion of detector
A body is dropped from a certain height h (h is very large) and second bodyis thrown downward with velocity of 5 m/s simultaneouly. What will be difference in heights of the two bodies after 3 s?
A source and an observer move away from each other with a velocity of 10 m/s with respect to ground. If the observer finds the frequency of sound coming from the source as 1950 Hz , then actual frequency of the source is (velocity of sound in air = 340 m/s )
A train moving at 40 m/s, passes by a stationary observer, emitting a whistle of frequency 300 Hz. If the velocity of sound wave is 340 m/s, then the change in the apparent frequency of the sound, just before and after the train passes by the observer will be nearly
A source of sound crosses a stationary observer which is moving with uniform velocity v. If the velocity of sound in air is V, then the ratio of the apparent frequencies heard by the observer before and after the source crosses him would be -
