The tiny ripples on the soup are not only similar to wind-generated
waves ... they ARE wind-generated waves. This is a big part of the
reason why they bear such an uncanny resemblance.
At the start of the 0.266 s, the object's speed was 8.26 m/s.
The question can only be talking about speed, not velocity.
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
Direction of resultant force in circular motion is directed towards the center of the circle. Hence vector B is the direction of the resultant force.