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Homework Help: Pistons force is in Newtons

  1. Nov 10, 2006 #1
    Piston 1 has a diameter of 0.34 in. Piston 2 has a diameter of 1.0 in. In the absence of friction, determine the force, necessary to support the 500 lb weight over piston 2.

    I used F(1) = pi(r1^2)/pi(r2^2)*F(2)

    and got the wrong answer. I used radii of .17in and .5in. Is that the right formula? Do I need to convert the units to something else?
    Last edited by a moderator: Mar 7, 2013
  2. jcsd
  3. Nov 10, 2006 #2
    Well if your force is in Newtons, then you would need to convert the inches to meters.
  4. Nov 10, 2006 #3
    I get the same answer!?!

    We know that F1=P A1 and F2=P A2, solve 2 for P, P = F2/A2 and substitute.

    F1 = F2/A2 A1

    I get 57.8 Pounds which makes sense.
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