Unit One: What forces will take a plane in the air?

Aairplane

An airplane or aeroplane (informally plane) is a powered, fixed-wing aircraft that is propelled forward by thrust from a jet engine or propeller. Airplanes come in a variety of sizes, shapes, and wing configurations. The broad spectrum of uses for airplanes includes recreation, transportation of goods and people, military, and research. Commercial aviation is a massive industry involving the flying of tens of thousands of passengers daily on airliners. Most airplanes are flown by a pilot on board the aircraft, but some are designed to be remotely or computer-controlled.

What forces will take an airplane in the air?

Any textbook that talks about airplanes always discusses the four forces affecting an airplane: lift, weight, thrust and drag. Three of those forces are obvious to us.

1.Weight

Everyone weighs himself or herself on the bathroom scale every morning, so weight is easy to understand. Weight is a force caused by gravity which keeps us on the ground.

2.Thrust

Household fans produce thrust (at least a little) in the same way a propeller does, so that concept is familiar. The propeller that is drived by an engine creates thrust and moves the plane forward.

3.Drag

Anyone who has ever stuck his or her hand out the window of a car on the freeway has felt the effects of drag. The force that pushes your hand back is called "drag".

4.Lift

But life - there's something uncommon. If lift were easy we could stick out our arms and fly like a bird! But obviously it is not that easy.

Question:

1.Have you ever taken an airplane before? How do you feel in the air?

2.Have you ever been curious about how an airplane can fly?

2.Have you had ideas about that? Discuss your ideas with your classmates.

References

The 4 forces of flight: https://www.mansfieldct.org/Schools/MMS/staff/hand/flight4forcesoverview.htm

NASA Education: http://www.nasa.gov/audience/forstudents/k-4/stories/ames-how-do-planes-fly-text.html