## Acceleration Problems

We are now going to determine how much acceleration is produced by a jet engine mounted in an aircraft.

Newton's second law of motion gives a definition of force:

Force = mass X acceleration

which scientist would abbreviate by the equation: F = m a

From the Level 1 lesson on Weights and Mass, you know how to compute the mass of an airplane if you are given the weight. The jet engines will produce a force called thrust which we will learn about in later lessons. The thrust of the engines push the aircraft through the air. If the thrust is the only force acting on the airplane, you can use the above equation to compute the acceleration which the airplane experiences. (On real airplanes, there is aerodynamic drag produced because of the aircraft's velocity. Drag opposes the thrust and real airplanes are accelerated by a force equal to the difference between the thrust and the drag. For this set of problems, we are going to neglect the drag, so our answers may not be very realistic. Another force which we will neglect is the friction between the ground and our wheels during takeoff.)

Now you are the pilot. Look on the Engine Control Panel and find the weight of the airplane. If you are doing the Easy Force Problems, the computer has calculated the airplane's mass for you and it is given as part of the problem. If you are doing the Hard Force Problems, you must compute the mass of the airplane using the results from Level 1. Find the Thrust on the instrument panel at the lower left. Then compute how fast the plane can accelerate using the calculator and the force equation given above. You can either enter your answer into the white display box labeled "Accel" or you can choose a "Multiple Choice" answer. When you think you have the correct answer, push the "SUBMIT ANSWER" button.

Push the "New Problem" button to get a new set of conditions to work on. You can also change the type of aircraft for these problems.

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