Answer:
Person B
Explanation:
Person B will hear the frequency that is lower than the B- flat.
displacement is given by equation

now at t = 5 s the position is

similarly position at t = 9 s

so the displacement of object in given interval of time will be

time interval

now the average velocity will be given as


so its average speed is 252 m/s
The work-energy theorem states that the change in kinetic energy of the particle is equal to the work done on the particle:

The work done on the particle is the integral of the force on dx:

So, this corresponds to the change in kinetic energy of the particle.
If you mark off a beginning time and ending time on the graph,
then the area under the part of the graph between those limits
is the distance covered during that period of time.