Source and Listener Moving in Different Lines

Q. 16. A body executing S.H.M. along a straight line hasa velocity of 3 ms-1 when it is at a distance of4 m from its mean position and 4 ms-1 when it isat a distance of 3 m from its mean position. Its angular frequency and amplitude are

Q. A vehicle, with a horn of frequency n, is moving with a velocity of 30 m/s in a direction perpendicular to the straight line joining the observer and the vehicle. The observer perceives the sound to have a frequency n + n₁. Then n₁ is equal to (take velocity of sound in air as 330 m/s)

1. $n_1=10n$
2. $n_1=-n$
3. $n_1=0.1n$
4. $n_1=0$

Q. A vehicle, with a horn of frequency n is moving with a velocity of 30 m/s in a direction perpendicular to the straight line joining the observer and the vehicle. The observer perceives the sound to have a frequency n + n1. Then : (Take velocity of sound in air 330 m/s) : (1) n1 = 10 n (2) n1 = –n (3) n1 = 0 (4) n1 = 2n

Q. Two trains $A$ and $B$ simultaneously start moving along parallel tracks from a station along same direction. A starts with constant acceleration $2{\text{m/s}}^2$ from rest while $B$ with the same acceleration but with initial velocity of $40\text{m/s}$. Twenty seconds after the start, passenger of $A$ hears whistle of $B$. If frequency of whistle is $1194\text{Hz}$ and velocity of sound in air is $322\text{m/s}$, then the frequency observed by the passenger is

1. $1186\text{Hz}$
2. $1086\text{Hz}$
3. $986\text{Hz}$
4. $886\text{Hz}$

Q.

Two cars are moving on two perpendicular roads towards a crossing with uniform speeds of 72 km/hr and 36 km/hr. If first car blows horn of frequency 280 Hz, then the frequency of horn heard by the driver of second car when line joining the cars make ${45}^{\circ }$ angle with the roads; will be

1. 321 Hz

2. 298 Hz

3. 289 Hz

4. 280 Hz

Q.

A train has just complicated a U-curve in a track which is a semicircle. The engine is at the forward end of the semi circular part of the track while the last carriage is at the rear end of the semicircular track. The driver blows a whistle of frequency 200 Hz. Velocity of sound is 340 m/sec. Then the apparent frequency as observed by a passenger in the middle of a train when the speed of the train is 30 m/sec is

1. 288 Hz

2. 181 Hz

3. 200 Hz

4. 209 Hz

Q. 20. particle performs simple harmonic motion with an amplitude of 4 cm. At the mean position the velocity of the particle is 10cm/s. The distance of the particle from the mean position when its speed becomes 5cm/s is (1)\sqrt{}3cm (2)\sqrt{}5cm (3)2\sqrt{}3cm (4)2\sqrt{}5cm

Q. 12.Two cars are moving on two perpendicular roads towards a crossing with uniform speed of 72km/h and 36km/h. if fast car blows horn of frequency 300Hz then the frequency of hornr heard by the driver of second car when line joining the cars make 45 degree angle with the roads will be.? speed of sound 330m/s

Q.

A train has arrived into a track which is a semicircle. At an instant when the engine is at the forward end of the semi circular part of the track while the last carriage is at the rear end, the driver blows a whistle of frequency 200 Hz. Velocity of sound is 340 m/sec. Then the apparent frequency as observed by a passenger in the middle of the train at the same instant is, (the speed of the train is 30 m/second)

1. 209 Hz

2. 288 Hz

3. 200 Hz

4. 181 Hz

Q. A person standing on a road sends a sound signal to the driver of a car going away from him at a speed of 72 km h⁻¹. The signal travelling at 330 m s⁻¹ in air and having a frequency of 1600 Hz gets reflected from the body of the car and returns. Find the frequency of the reflected signal as heard by the person.

Q. A vehicle, with a horn of frequency n is moving with a velocity of 30 m/s in a direction perpendicular to the straight line joining the observer and the vehicle. The observer perceives the sound to have a frequency n + n1. Then : (Take velocity of sound in air 330 m/s) : (1) n1 = 10 n (2) n1 = –n (3) n1 = 0 (4) n1 = 2n

Q. why is omega at same time called angular velocity and also angular frequency?

Q. police man blows a whistle calculate the changewith frequency of 500hz a car moves
towards him with velocity 15m/s calculate the change in frequency heared by driver of the car before and after crossing the police man [speed of sound in air is 300m/s]

Q. A train moving at a speed of $30\text{m/s}$ has just completed a U-curve in a semi-circular track. The engine is at the forward end of the semi-circular part of the track while the last carriage is at the rear end of the semi-circular track. The driver blows a whistle of frequency $200\text{Hz}$. If the velocity of sound is $340\text{m/s}$, then the apparent frequency as observed by a passenger in the middle of the train is

1. $219\text{Hz}$
2. $188\text{Hz}$
3. $200\text{Hz}$
4. $181\text{Hz}$

Q. B) A train passing through a station with velocity 80 m/s by blowing horn at frequency 512 Hz. Calculate the frequency of sound heard a person standing on a platform.
(i) When the train is approaching.
(ii) When the train is receding.

Q. a particle is in shm with amplitude A and has a maximum vel v (1)at what displacement will the velocity be v/2 (2)what is the velocity at displacement A/2