Physics-
General
Easy
Question
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
- 209 Hz
- 288 Hz
- 200 Hz
- 181 Hz
The correct answer is: 200 Hz
The situation is shown in the fig.
Both the source (engine) and the observer (Person in the middle of the train) have the same speed, but their direction of motion is right angles to each other. The component of velocity of observer towards source is and that of source along the time joining the observer and source is also . There is number relative motion between them, so there is no change in frequency heard. So frequency heard is 200 Hz.
Related Questions to study
Physics-
If and then projection of on will be
If and then projection of on will be
Physics-General
Physics-
A particle is moving on a circular path of radius r with uniform velocity v. The change in velocity when the particle moves from P to Q is
A particle is moving on a circular path of radius r with uniform velocity v. The change in velocity when the particle moves from P to Q is
Physics-General
Physics-
Figure below shows a body of mass M moving with the uniform speed on a circular path of radius, R. What is the change in acceleration in going from to
Figure below shows a body of mass M moving with the uniform speed on a circular path of radius, R. What is the change in acceleration in going from to
Physics-General
Physics-
A metal sphere is hung by a string fixed to a wall. The sphere is pushed away from the wall by a stick. The forces acting on the sphere are shown in the second diagram. Which of the following statements is wrong
A metal sphere is hung by a string fixed to a wall. The sphere is pushed away from the wall by a stick. The forces acting on the sphere are shown in the second diagram. Which of the following statements is wrong
Physics-General
Physics-
The equation represents a wave with
The equation represents a wave with
Physics-General
Physics-
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
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
Physics-General
Physics-
Two vectors and will be parallel if
Two vectors and will be parallel if
Physics-General
Physics-
A particle is moving on a circular path of radius r with uniform velocity v. The change in velocity when the particle moves from P to Q is
A particle is moving on a circular path of radius r with uniform velocity v. The change in velocity when the particle moves from P to Q is
Physics-General
Physics-
Figure below shows a body of mass M moving with the uniform speed on a circular path of radius, R. What is the change in acceleration in going from to
Figure below shows a body of mass M moving with the uniform speed on a circular path of radius, R. What is the change in acceleration in going from to
Physics-General
Physics-
A metal sphere is hung by a string fixed to a wall. The sphere is pushed away from the wall by a stick. The forces acting on the sphere are shown in the second diagram. Which of the following statements is wrong
A metal sphere is hung by a string fixed to a wall. The sphere is pushed away from the wall by a stick. The forces acting on the sphere are shown in the second diagram. Which of the following statements is wrong
Physics-General
Physics-
The length of second's hand in watch is 1 cm. The change in velocity of its tip in 15 seconds is
The length of second's hand in watch is 1 cm. The change in velocity of its tip in 15 seconds is
Physics-General
Physics-
Figure shows ABCDEF as a regular hexagon. What is the value of
Figure shows ABCDEF as a regular hexagon. What is the value of
Physics-General
Physics-
Find the resultant of three vectors and shown in the following figure. Radius of the circle is R.
Find the resultant of three vectors and shown in the following figure. Radius of the circle is R.
Physics-General
Physics-
From the equation , one can obtain the angle of banking for a cyclist taking a curve (the symbols have their usual meanings). Then say, it is
From the equation , one can obtain the angle of banking for a cyclist taking a curve (the symbols have their usual meanings). Then say, it is
Physics-General
Physics-
Number of particles is given by crossing a unit area perpendicular to X-axis in unit time, where and are number of particles per unit volume for the value of meant to and . Find dimensions of called as diffusion constant
Number of particles is given by crossing a unit area perpendicular to X-axis in unit time, where and are number of particles per unit volume for the value of meant to and . Find dimensions of called as diffusion constant
Physics-General