Lesson5_ApparentWeight&Weightlessness.notebook
November 06, 2013
Apparent Weight and Weightlessness
Your "weight" is a measure of the force of gravity acting upon you, and is reflected in the magnitude of the normal force, FN. Any acceleration, such as from an elevator, can make you "feel" heavier or lighter. This new Normal Force is your "apparent weight"
*notice that if you are stationary or moving with uniform motion, your apparent weight is the same as your actual weight.
If you are moving in a vertical circle with enough velocity, this Normal force will reduce to zero. When this happens you are said to be "weightless"
*it doesn't mean you have no mass, but that if you were sitting on a bathroom scale at that time it would read "zero".
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Lesson5_ApparentWeight&Weightlessness.notebook
November 06, 2013
why_doesnt_the_moon_fall_down.mp4
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Lesson5_ApparentWeight&Weightlessness.notebook
November 06, 2013
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Lesson5_ApparentWeight&Weightlessness.notebook
November 06, 2013
*Notice that apparent weight requires a mass, but weightless problems are independent of mass.
Ex: A 65.0 kg person is moving through a vertical circle of radius 35.0 m at a speed of 27.0 m/s. a) Find her apparent weight at the top and at the bottom of the loop. b) What speed would be required in order for her to feel weightless? (FN = 0)
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Lesson5_ApparentWeight&Weightlessness.notebook
FN (bottom) = 1990 N
November 06, 2013
FN (top) = 717 N
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Lesson5_ApparentWeight&Weightlessness.notebook
November 06, 2013
*Notice that apparent weight requires a mass, but weightless problems are independent of mass.
b) v = 18.5 m/s
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Attachments
why_doesnt_the_moon_fall_down.mp4