Biomechanics of Swimming: Thrust

Question 1

What is the density of water compared to air? What is the consequence?

Answer 1

• 800x
• support/buoyancy

Question 2

What is the velocity of water compared to air? What is the consequence?

Answer 2

• 50x
• drag

Question 3

Define velocity

Answer 3

• traction b/w molecules and fluid

Question 4

What does it mean that “water is incompressible”?

Answer 4

• fish exert force against
• thrust/propulsion

Question 5

What is BCF?

Answer 5

Body caudal fin propulsion

Question 6

What is the axial rod/vertebral column like? What does it provide?

Answer 6

• flexible and non-compressible
• provides muscle attachment

Question 7

How do fish generate thrust?

Answer 7

• propulsive wave

Question 8

What is a propulsive wave?

Answer 8

• muscle contraction that waves head –> tail

Question 9

in vector diagrams, the _________ _____ cancels out. What does this do?

Answer 9

• lateral component
• wastes energy

Question 10

If the lateral component didn’t cancel out, how would fish move?

Answer 10

more side to side

Question 11

In thrust generation (vector diagram) thrust is ____. which causes what?

Answer 11

• thrust is additive
• causes forward movement

Question 12

In vector diagrams, the side to side movement is on what axis?

Answer 12

X

Question 13

In vector diagrams, the head to tail movement is on what axis? What does this cause?

Answer 13

• Y
• Thrust

Question 14

What relationship do the reactive force and push have while a fish is moving?

Answer 14

• equal but opposite reaction
• moves fish forward