Astreet musician sounds the a string of his violin, producing a tone of 440 hz, what frequency does a bicyclist hear as he a) approaches and b) recedes from the musician with a speed of 11.0 m/s?

a)

b)

Explanation:

Let´s use Doppler effect, in order to calculate the observed frequency by the byciclist. The Doppler effect equation for a general case is given by:

where:

Now let's consider the next cases:

The data provided by the problem is:

The problem don't give us aditional information about the medium, so let's assume the medium is the air, so the speed of sound in air is:

Now, in the first case the observer alone is in motion towards to the source, hence:

Finally, in the second case the observer alone is in motion away from the source, so:

like poles repel so keep pushing north to north and repels funny to see this

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y