The Physics of Bird Flight

5th Grade

Objectives:

• To explain how a bird is able to fly

• To identify three types of flight that birds use.

Did you know?

• All objects on land are surrounded by an invisible ocean of air.

• Air = a mixture of gas molecules that exert pressure on the objects they surround.

Air Pressure:

• When you blow into a balloon, it gets larger

• The pressure of the air molecules pushing on the sides of the balloon make it expand

Air Pressure: How does it work?

Air Pressure: How does it work?

Air Pressure

• The faster air moves, the less pressure it exerts

Movement and Air Pressure

For birds, fast-moving air above the wing exerts less pressure

Slower-moving air below the wing exerts more pressure

Higher pressure keeps the bird in flight

A bird’s angle and shape of the wing causes the air to move faster above the wing than below it

Lift: an upward force that causes a bird to rise based on the difference in pressure above and below the wings as a bird moves

through the air

What does a bird do to get off of the ground before it uses lift to fly?

To get into the air….

• A bird moves forward to make air move over its wings

• A bird sharply pulls down its wing to provide the power that pushes the bird forward

Once birds are in the air, there are 3 types of bird flight

• 1) ?

• 2) ?

• 3) ?

Three types of bird flight:

• 1) Flapping

• 2) Soaring

• 3) Gliding

Flapping: what does that do?

Flapping

• All birds flap their wings (sharply pull down their wings)

• Certain birds rely on flapping more than others

Soaring

• Involves little movement

• Birds use rising currents of warm air

• Used to move upward

Gliding

• Involves little wing movement

• Birds use falling currents of cool air

• Used to move downward

Question: Does Soaring or Flapping take more energy?

Answer: Flapping…it takes a large amount of energy!

What do birds use so that they do not need to waste too much energy on flapping?

They use warm and cool air currents

Did you know? Warm air rises and cool air sinks

Remember that to soar, birds use warm air currents so that they can move upward

Remember that to glide, birds use cold air currents so that they can move downward

What is a type of flight that we have not yet talked about that doesn’t use any lift?

Answer: Diving does not use any lift.

• How do birds use diving to their advantage?

Diving is used for…

• Hunting for prey

What does a bird do with its wings so that it can effectively dive?

Birds pull their wings in close to their bodies so that there is no more lift

• The result: gravity pulls them down!

• Fun fact: Peregrine Falcons can dive up to 300 kilometers per hour

Peregrine Falcon Diving

• http://www.youtube.com/watch?v=j3mTPEuFcWk

Bird Flight: This video really helps explain it!

• http://www.youtube.com/watch?v=3So7OMwNgy8