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- You just managed to land your plane on a deserted island. The field is so
- short that you were barely able to bring the plane to a stop without
- running into the trees. Now you wonder whether you will be able to leave.
- Is this field long enough to take off? You know precisely how much runway
- is needed for a takeoff with this plane, but you don't have a measuring
- tape or a yard stick to measure the field.
-
- After a while, you realize that you do have a piece of string and a stop
- watch. You tie a small object to the end of the string and make yourself a
- pendulum. You know that on earth the gravitational acceleration, g, doesn't
- vary much and that 9.8 m/s^2 is a fairly accurate value of g for
- intermediate latitudes. Now you can find the length of your string and then
- use the string to measure the field!
-
- To simulate this situation I have hidden the vertical scale and I will also
- change that scale and the pendulum each time you do the assignment. Measure
- the period carefully, remembering that the simple pendulum formula is very
- accurate as long as you keep the oscillation amplitude smaller than about
- 20 degrees. Calculate the length, check your measurement and your
- calculations and then press F2 to enter your answer.