A2: Fluid Mechanics

Question 1

What is fluid mechanics?

Answer 1

The study of the forces acting on a body travelling through the air or water

Question 2

Definition of drag (D):

Answer 2

The force that opposes the direction of motion of a body through water (e.g. swimming)

Question 3

Definition of air resistance (AR):

Answer 3

The force the opposes the direction of motion and acts on a body travelling at high velocity (e.g. cycling, sprinting)

Question 4

What 4 factors affect AR and D?

Answer 4

Velocity
Front cross-sectional area (FCSA)
Streamlining and shape
Surface characteristics

Question 5

How does velocity affect AR and D?

Answer 5

Greater velocity = Greater AR and D

(velocity is the only factor that you do not want to change in sporting performance

Question 6

How does front cross-sectional area affect AR and D?

Answer 6

Greater FCSA = Greater AR and D

Question 7

How does streamlining and shape affect AR and D?

Answer 7

More aerodynamic = Lower AR and D

Question 8

How do surface characteristics affect AR and D?

Answer 8

Smoother surface = Lower AR and D

Question 9

What is the relationship between pressure and velocity?

Answer 9

Inversely proportional: High velocity = Low pressure (and vice versa)

Question 10

Definition of aerofoil:

Answer 10

A streamlined shape with a curved upper surface and flat lower surface to provide additional lift force