To solve this problem we will apply the concepts related to the Doppler effect. According to this concept, it is understood as the increase or decrease of the frequency of a sound wave when the source that produces it and the person who captures it move away from each other or approach each other. Mathematically this can be described as

Here,
= Original frequency
= Velocity of the observer
= Velocity of the speed
Our values are,



Using the previous equation,

Rearrange to find the velocity of the observer

Replacing we have that


Therefore the velocity of the observer is 16.2m/s
The study of how the world works
A succession of single tones or pitches perceived as a unit is called a melody. It is a linear succesion of tones in music that is seen as one single entity. It is a combination of rhythm, pitch and tonal color. Melodies usually has one ormore motifs or phrases that are being repeated all throughout a composition. Melodies are characterized by the melodic motion it posses , the pitch, intervals between the pitches, continuity and pitch range. Due to the a wide range of melodies that can be made from tones, differet genres of music arise. Examples are Jazz, Rock music, Classical, pop, R&B and the like.
Human cells don't have<span> a </span>cell wall<span> in the same way that plants </span>do. We<span> </span>have cell<span> membranes which are more malleable structures than the </span>rigid cell walls<span> of plants.</span>
Answer:

Explanation:
By conservation of energy, the sum of the kinetic and gravitational potential energies at the surface of the Earth must be equal than their sum at infinity, so we have:


Where
is the gravitational constant,
and
are the mass and radius of the Earth, <em>m </em>is the mass of the particle,
its velocity at the surface of the Earth (which would be its escape velocity) and
and
are the velocities and distance at infinity, which would be null and infinity respectively, so the right hand side of our equation is 0J, which leaves us with:

Also, since the force the molecule experiments is the force of gravity (disregarding drag), we can write its weight in terms of Newton's Law of Gravitation:

Which means that:

So finally putting all together we can write:
