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Homework Help: Work Done by Air Resistance

  1. Mar 29, 2005 #1
    A 3.51 x 10^5 kg raindrop falls vertically at
    constant speed under the influence of gravity
    and air resistance.
    The acceleration of gravity is 9.8 m/s^2 :
    After the drop has fallen 115 m, what is the
    work done by air resistance?

    would it be opposite of that done by gravity which i found to be 3.955 x 10^-2???
  2. jcsd
  3. Mar 29, 2005 #2


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    Last edited: Mar 29, 2005
  4. Mar 29, 2005 #3


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    Yes,"constant speed" means that the 2 forces are perfectly balanced.Since they act on the same distance,u could say the the workd done by gravity is equal in modulus with the one done by friction force.

  5. Mar 29, 2005 #4


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    Since the raindrop is falling at constant speed, the net force on it is 0. That means that the air resistance force is equal to but opposite the force of gravity. The work done is just that force times the 115 m distance.
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