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Terminal speed question

  • Thread starter Steelers72
  • Start date
  • #1
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Homework Statement


A 82kg skydiver can be modeled as a rectangular "box" with dimensions 21cm× 44cm× 1.8m

Homework Equations


v = sqrt(2mg/(rho * C *A))

The Attempt at a Solution



A = 0.21 m * 0.44 m = 0.0924 m^2

v = sqrt(2 * 82 kg * 9.81 m/s^2 / (1.2 kg/m^2 * 0.0924 m^2 * 0.80))
=135m/s


Apparently this is wrong. I have tried many other formulae but I haven't had luck and I have one more attempt remaining. Any ideas?
 

Answers and Replies

  • #2
Svein
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Why are you assuming that he dives "head first"?
 
  • #3
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Why are you assuming that he dives "head first"?
the question doesnt suggest otherwise, doesn't specify if he dives head first or legs first.
 
  • #4
SteamKing
Staff Emeritus
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the question doesnt suggest otherwise, doesn't specify if he dives head first or legs first.
What if the skydiver takes this attitude, before the parachute opens?

freefall2.jpg
 
  • #5
54
10
What if the skydiver takes this attitude, before the parachute opens?

freefall2.jpg
Agreed! Take the largest surface of the box as area.
 

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