Air and Aerodynamics

Question 1

What is air?

Answer 1

all around us
air is mass
air is a fluid
air is matter - air takes up space
pushes on objects
has an insulating property

Question 2

What is air composed of?

Answer 2

78% nitrogen, 21% oxygen, 1% argon and trace gases

Question 3

How can you prove the presence of oxygen and carbon dioxide?

Answer 3

carbon dioxide - take a balloon and blow into it - the carbon dioxide you breathe out fills the balloon

oxygen - if you breathe in your stomach expands a little, it’s the oxygen that makes your stomach expand,

Question 4

How can you make carbon dioxide?

Answer 4

by breathing out

Question 5

Does air exert pressure?

Answer 5

yes - in all directions

Question 6

How can you prove air exerts pressure?

Answer 6

Although air is invisible, you may be able to see the change in pressure when the air moves from an area of high pressure to low pressure pushing an object with it.

on a windy day it is the air blowing, a kite being blown around, a balloon floating away, leaves blowing around

Question 7

How much pressure does air exert?

Answer 7

1 kilogram of air presses on each square cm of your body

When something isn’t moving the air pressure around it is equal in all directions; when you stand still the pressure holding you down is the exact same as the pressure holding you up.

Question 8

Does air have weight? (mass)

Answer 8

yes

Question 9

How can you prove air has weight?

Answer 9

An inflated balloon will weigh more than an empty or popped balloon.

Question 10

Can air be compressed?

Answer 10

yes

Question 11

How can you prove air can be compressed?

Answer 11

The air inside an inhaler is squeezed into the compact container therefore it is compressed

Question 12

What are examples of high air pressure situations?

Answer 12

the air on the straight part of the airfoil, when you blow on a piece of paper attached to your chin the high pressure is below the paper, when you blow on a u shaped cue card the high pressure area is on the sides, when on a ping pong ball through a cone the high pressure is below the ball, gravity, the air outside a suction cup, high heels

Question 13

What are examples of low air pressure situations?

Answer 13

the air on the curved part of the airfoil, when you blow on a piece of paper attached to your chin the low pressure is above it, when you blow on a u shaped cue card the low pressure area is on the top of the underside, when you blow on a ping pong ball through a cone the low pressure are is on the sides, the air inside a suction cup, mud shoes,

Question 14

Why is air considered a fluid?

Answer 14

air is considered a fluid because it flows

Question 15

How can you prove air is a fluid?

Answer 15

you can prove air is a fluid by turning on a fan and throwing something like paper or glitter towards it and then waving your hand in front of the air flow deforming it und the shear stress . This is something that fluids do

Question 16

How is air affected by hot temperatures?

Answer 16

When air turns hot it rises since it becomes less dense it also takes up more space and expands

Question 17

How is air affected by cold temperatures?

Answer 17

When air is cold it becomes more dense and sinks taking up less space and contracting or shrinking

Question 18

What is Bernoulli’s principle?

Answer 18

Bernoulli’s principal is the airfoil in which has a curved top and a flat bottom and states that the air on top will go faster due to compression and create low pressure and the air flowing along the bottom will flow slower creating high pressure and that the high pressure will want to get to the low pressure pushing the airfoil up

Question 19

How can you apply Bernoulli’s principle and explain the results?

Answer 19

Bernoulli’s principal is applied on airplanes when they fly. The results are lift that comes when the slow and high pressure air is pushing towards the fast and low pressure area along the curved to pushing the airfoil up and creating lift.

Question 20

What are the 4 forces of flight?

Answer 20

lift, thrust, drag, mass/gravity/weight

Question 21

Explain each force of flight in your own words.

Answer 21

lift- this is the force of flight needed to get the flying object off the ground.
thrust- this is the force that propels the object forward through the air.
drag-this is the force that tries to hold the plane back and prevent it from going forwards.
mass/gravity/weight- this is the force opposing lift and it tries to drag the object closer to the ground

Question 22

Which forces have to be greatest to have flight?

Answer 22

lift and thrust

Question 23

What determines the amount of gravity?

Answer 23

the closer you are to the equator, the greater the level of gravity whereas the farther you are from the equator the less gravity there is.

Question 24

What creates lift?

Answer 24

lift is created by an airfoil, this is a wing curved at the the top and straight on the bottom. The air flowing over the top of the airfoil is being squeezed and compressed by the air above it creating low pressure, while the air flowing along the bottom of the wing is flowing smoother and more straight creating high pressure. No matter high air pressure tries to get to the low pressure pushing the wing up.

Question 25

What creates thrust?

Answer 25

birds rotate their wing in a circular motion to help propel themselves forward generating thrust while planes either use jets or propellers to generate thrust.

Question 26

What creates drag?

Answer 26

drag is created when the air pressure propelling the object forward is less than the pressure pulling it backwards.

Question 27

What is streamlining and how does it reduce drag?

Answer 27

streamlining is when modifications are made to something to help reduce drag by using specific clothing equipment body position etc. all with a smooth easy for air to flow over shape.

Question 28

What are real world applications of streamlining?

Answer 28

streamlining is used a lot in sports such as skiing where they use skintight suits slick skis and a squatted body position. In cycling they use special helmets suits and a hunched position while in swimming they use slick suits and caps.

Question 29

What are the forces exerted on a parachute?

Answer 29

on parachutes they have a hole in the middle of the canopy to affect it’s stability while the size of the canopy will affect the speed at which it falls.