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Homework Help: Centripetal Force

  1. May 24, 2010 #1
    1. The problem statement, all variables and given/known data

    An airplane is flying in a horizontal circle at a speed of 141 m/s. The 94.2 kg pilot does not want his radial acceleration to exceed 8.88g

    What is the minimum radius of the circular path?


    2. Relevant equations
    v^2/r

    3. The attempt at a solution
    141^2/.00888 kg
     
  2. jcsd
  3. May 24, 2010 #2
    try using v^2/r<=8.88g
     
  4. May 24, 2010 #3
    i dont think u have to take gravity cause its perpendicular to radial acceleration and it really has no effect (its a horizontal circle)
     
  5. May 24, 2010 #4
    yeah i realized that as soon as i wrote it. i was thinking centripetal acceleration and vertical circle, dont know where i got that from
     
  6. May 24, 2010 #5
    i dont know why they gave the pilots mass, it wont affect radial acceleration will it?
     
  7. May 24, 2010 #6
    with your attempt why do you have 0.00888kg? a_C =v^2/r r=141^2/9.81*8.888? = 228
     
  8. May 24, 2010 #7
    how does a helicopter lift-off?
     
  9. May 24, 2010 #8
    evidently it will but are the pilot and the plane one entity??? or are they considered as two separate masses. sorry im asking more questions than djb991 i just covered this topic and dont understand it too well.
     
  10. May 24, 2010 #9
    sorry, completely misread about half of that problem. then yes, the mass of the pilot seems pretty insignificant considering the mass of the airplane.
     
  11. May 24, 2010 #10
    is there anything you can see wrong with what ive done here? except the a_c should be a_r and there should be brackets around the bottom half.
     
  12. May 24, 2010 #11
    pilot n airplane r considered as one entity
    pilots mass or even the whole system mass wont affect its radial acceleration as its moving in a horizontal circle
    141*141/r=8.88*9.8
     
  13. May 24, 2010 #12
    yep thats exactly what I thought and said
     
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