# data[].attributes.body
A tube with a U-shape contains some water. IF you blow air across one mouth of the tube, the water level on that mouth will actually rise and the water level on the other mouth will drop.

# data[].attributes.headline
How is it possible for an airplane to stay in the air?

# data[].attributes.subject
How is it possible for an airplane to stay in the air?

# data[].attributes.body
It has got something to do with Bernoulli's Principle.
Just to recap, if the upward force of an object is equal to the downward force of the object, it will remain at its vertical position; if the upward force is larger than the downward force, the object will ascend; if the downward force is larger than the upward force, the object will descend.

The cross-sectional area of an airplane wing looks like a semicircle(but not really). Note that the air blowing across the wing will create different pressure. The top of the wing looks rounded whereas the bottom is flat. Air will move faster when travelling on top of the wing than on the bottom of the wing because the air must reach the end of the wing at the same time(A longer distance is travelled by the air on top since I is rounded). Thus, the speed of the air above the wing is faster, resulting in lower pressure and the speed of the air below the wing is slower, resulting in higher pressure.
Therefore, the pressure below the wing actually exers an upward force on the plane wing, causing the plane to fly upwards.

# data[].attributes.headline
Another example of Bernoulli's Principle

# data[].attributes.subject
Another example of Bernoulli's Principle

# data[].attributes.body
When we use a hair dryer to blow a table-tennis ball upwards, the ball will move around the hair dryer.

# data[].attributes.body
when the speed of a fluid increase, its pressure decreases