6 is b. part B on 6 is a. 7 is a. partB ON 7 b
Answer:

Explanation:
We define our values according to the text,
R= Radius
Velocity
Strenght of the vortex filament
From this and in a vectorial way we express an elemental lenght of this filmaent as
. So,

Where
imply a vector acting perpendicular to both vectors.
Applying Biot-Savart law, we have,

Substituting the preoviusly equation obtained,



So we can express the velocity induced is,

The answer is D. Digestive! The digestive system breaks down your food and helps to eliminate waste!