Page 39 - ebook fluid mechanics_finalize

FLUID MECHANICS

C. the small piston is 0.40 m below the larger piston

p = p + 
gh
1
2
W
p =
2
A

3
Putting ρ 10 kg= 3 / m , g = 9.81 m/s and h = 0.40 m
2

p = p + 
gh
1
2
so p = W +  gh
1
A

F
but p1 =
a

F = W +  gh
a A

 650 
 F  A =  − 1000  . 9 81 4 . 0  150x 10 − 4
so W =  −  gh − 4
 a   15x 10 

W = 6441.14 N

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