Fluid mechanics - lift

Question 1

What is the Bernoulli Principle?

Answer 1

Where air molecules exert less pressure the faster they travel and more pressure when they travel slower

Question 2

What directions can a lift force be?

Answer 2

Upward and downward

Question 3

What happens if the lift force is in an upward direction?

Answer 3

It will keep an object in the air for longer, therefore increasing its horizontal displacement

Question 4

What happens if the lift force is in a downward direction?

Answer 4

It will force an object towards the ground, therefore increasing the amount of friction generated with the ground

Question 5

When is lift achieved?

Answer 5

When both low and high air pressures act on an object

Question 6

Where does high air pressure come from?

Answer 6

Slow air

Question 7

Where does low air pressure come from?

Answer 7

Fast air

Question 8

What happens if an objects flight is parallel to the ground?

Answer 8

It will not be forced upwards or downwards because the air flowing over and under the object is moving at the same speed. As there is no difference between the speed of the air, air pressure remains the same.

Question 9

When is a lift force generated?

Answer 9

When an object is tilted into the air flow
When an object is tilted it changes the flow of air around an object
If the air has to travel further due to this change, it will increase in velocity
This increase in air velocity leads to lower air pressure