Home
Class 12
PHYSICS
A car approaching a crossing C at a spe...

A car approaching a crossing `C` at a speed of `20 m//s` sounds a horn of frequency `500 H_(Z)` when `80 m` from the crossing . Speed of sound in air is `330 m//s` . What frequency is heard by an observer (at rest) `60m` from the crossing on the straight road which crosses car road at right angles ?

Text Solution

Verified by Experts

The situation is as shown in figure. `cos theta=(80)/(100)=(4)/(5)`

`f_(app)=((V)/(V-Vcos theta))f=((330)/(330-20xx(4)/(5)))(500)`
`=525.5Hz`
Promotional Banner

Topper's Solved these Questions

  • WAVES

    AAKASH SERIES|Exercise EXERCISE-IA (Theoretical questions :)|85 Videos

  • WAVES

    AAKASH SERIES|Exercise EXERCISE-IA (Statement type questions:)|18 Videos

  • WAVE OPTICS

    AAKASH SERIES|Exercise PROBLEMS (LEVEL - II)|33 Videos

  • WAVES OPTICS

    AAKASH SERIES|Exercise EXERCISE -III (POLARISITION)|10 Videos

Similar Questions

Explore conceptually related problems

A locomotive approaching a crossing at a speed of 80 mi/h sounds a whistle of frequency 400 Hz when 1 mi from the crossing. There is no wind, and the speed of sound in air is 0.200mi/s. What frequency is heard by an observer 0.60 mi from the crossing on the straight road which crosses the railroad at right angles?

A locomotive approaching a crossing at a speed of 80 mi/h sounds a whistle of frequency 400 Hz when 1 mi from the crossing. There is no wind, and the speed of sound in air is 0.200mi/s. What frequency is heard by an observer 0.60 mi from the crossing on the straight road which crosses the railroad at right angles?

A locomotive approaching a crossing at a speed of 20 ms^(-1) sounds a whistle of frequency 640 Hz when 1 km from the crossing. There is no wind and the speed of sound in air is 330 ms^(-1) . What frequency is heard by an observer sqrt(3) km on the straight road from the crossing at right angle :-

A train approachign a railway crossing at a speed of 120 kmh^-1 sounds a short whistle at frequency 640 Hz when it is 300 m away from the crossing. The speed of sound in air is 340 ms^-1 . What will be the frequency heard by a person standing on a road perpendicular to the track through the crossing at a distance of 400 m from the crossing ?

A source of sound of frequency 500 Hz is moving towards an observer with velocity 30 m/s . The speed of sound is 330 m/s . the frequency heard by the observer will be

A car is moving with a constant velocity 10 m//s towards the stationary wall. The car blows a horn of frequency 320 Hz . The velocity of sound in air is 330 m//s . The beats frequency received by the observer is

The driver of a car travelling with speed 30ms^-1 towards a hill sounds a horn of frequency 600 Hz. If the velocity of sound in air is 330ms^-1 , the frequency of reflected sound as heard by driver is

A police car horn emits a sound at a frequency 240 Hz. When the car is at rest. If the speed of the sound is 330 m/s the frequency heard by an observer who is approching the car at a speed of 11 m/s is

A car is approching a railway crossing at a speed of 72 kmph . It sounds a horn, when it is 800 m away, at 600 Hz . If the velocity of sound in air is 330 ms^(-1) . The apparent frequency as received by a man at rest near the railway track perpendicular to the road at a distance of 600 m from the crossing the

A source of sound of frequency 600Hz is placed inside of water. The speed of sound is water is 1500m//s and air it is 300m//s . The frequency of sound recorded by an observer who is standing in air is