6. One morning while waiting for class to begin, you are readinga newspaper article about airplane safety. This article emphasizesthe role of metal fatigue in recent accidents. Metal fatigueresults from the flexing of airframe parts in response to theforces on the plane especially during take off and landings. As anexample, the reporter uses a plane with a take off weight of200,000 lbs and take off speed of 200 mph which climbs at an angleof 30o with a constant acceleration to reach its cruising altitudeof 30,000 feet with a speed of 500 mph. The three jet enginesprovide a forward thrust of 240,000 lbs by pushing air backwards.The article then goes on to explain that a plane can fly becausethe air exerts an upward force on the wings perpendicular to theirsurface called \"lift.\" You know that air resistance is also a veryimportant force on a plane and is in the direction opposite to thevelocity of the plane. The article tells you this force is calledthe \"drag.\" Although the reporter writes that some metal fatigue isprimarily caused by the lift and some by the drag, she never tellsyou their size for her example plane. Luckily the article containsenough information to calculate them, so you do.

1. Focus (on) the Problem.

2. Describe the Physics

3. Plan a Solution

4. Execute Your Plan

5. Evaluate the Answer