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A piston, A,has a diameter of 0.50 cm. A second piston, B has a diameter of 3.7...

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cmbrown12 | Student, Grade 11 | (Level 1) eNoter

Posted February 5, 2012 at 10:51 AM via web

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A piston, A,has a diameter of 0.50 cm. A second piston, B has a diameter of 3.7 cm.

Determine the force, F, necessary to support the 500.0 N weight in the absence of friction

Answer in Newtons

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ndnordic | High School Teacher | (Level 2) Associate Educator

Posted February 5, 2012 at 12:28 PM (Answer #1)

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You did not state on which piston the 500 N weight was placed.

Case 1: 500 N weight is on piston A.

In general, The P on A (Pa) = P on B (Pb)

But pressure = F/A, where F is the force in Newtons, and A is the area of the piston's surface,  so you have:

Fa/Aa = Fb/Ab

A = pi*r^2

Set up your equation, and Solve for Fb:

500/pi*(.25)^2 = Fb/pi*(1.85)^2

F = 27380 N

Case 2: 500 N weight is on piston B

Fa/pi*(.25)^2 = 500/pi*(1.85)^2

F = 9.1 N

By putting the weight on the larger piston, you gain a large mechanical advantage.

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