Bernoullis principle

Question 1

Bernoullis principle

Answer 1

being able to manipulate the flow of air around a projectile for it to go further.
- higher velocity that air travels, the lower surrounding pressure.

Question 2

Lift force

Answer 2

force created by a pressure gradient forming on opposing surfaces of an aerofoil moving through a fluid.

Question 3

Aerofoil shape

Answer 3

• curved upper surface and flat underneath surface.
• as the aerofoil moves through the air as it forced to part and flow at different velocities above and below the projectile to meet at the same time behind it.
• this affects the pressure of air flow above and below the aerofoil and a pressure gradient forms generating lift force.

Question 4

Characteristics of an aerofoil shape

Answer 4

• curved upper surface forces air flow to travel a further distance and move at a higher velocity
• flat underneath surface allows air to flow a shorter distance and at a lower velocity.

Question 5

Angle of attack

Answer 5

• the tilt of a projectile relatively to air flow

Question 6

No angle of attack

Answer 6

fluid on top goes the same distance in the same time as the fluid on the bottom.
- equal pressure above and below

Question 7

Angle attack

Answer 7

• greater pressure below the object than above the object, difference in pressure causes the lift force.

Question 8

Exam question - Explain how a ski jumper can apply Bernoullis principle to maximise the distance travelled through the air (5)

Answer 8

Bernoullis principle states that the higher velocity that air travels the lower surrounding pressure. The increased angle of attack would be the tilt or angle the athlete cuts through the air with, in this case the ski jumper who tilts their body downwards and flat to create an aerofoil shape which provides air to flow a shorter distance and at a lower velocity underneath. The difference in pressure above and below causes the lift force helping the athlete maximise its distance through the air.