Astationary bagpiper is playing a highland bagpipe, in which one reed produces a continuous sound of frequency 440 hz. the air is still and the speed of sound is 340 m/s. a) what is the wavelength of the sound wave produced by the bagpipe? b)what is the frequency of the sound wave that a bicyclist hears if she is approaching the bagpiper at 10.0 m/s? c)what is the wavelength of the sound wave that a bicyclist hears if she is approaching the bagpiper at 10.0 m/s? d)what is the frequency of the sound wave that a bicyclist hears if she is moving away from the bagpiper at 10.0 m/s? e)what is the wavelength of the sound wave that a bicyclist hears if she is moving away from the bagpiper at 10.0 m/s?

(A) 0.773 m

(B) f' = 452.94 Hz

(C)

(D) f" = 427.058 Hz

(E)

Solution:

As per the question:

Frequency of the sound produced, f = 440 Hz

Speed of the sound in still air, v = 340 m/s

Now,

(A) To calculate the wavelength of the sound wave:

We use the relation:

(B) By using Doppler effect to calculate the frequency of the sound wave:

Velocity of the receiver,

Velocity of the source,

When the receiver is approaching:

f' = 452.94 Hz

(C) To calculate the wavelength of the sound wave:

(D) While moving away, the frequency of the sound wave can be calculated as:

f" = 427.058 Hz

(E) The wavelength can be given by:

probably not if net force is zero

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.