Thursday, December 1
−
Lecture 34 :
Hydrostatics
(Refers to Section 7.6 in your text.)
Students who have mastered the content of this lecture know
:
the basic principles of the force
exerts on a wall due to hydrostatic pressure.
Students who have practiced the techniques presented in this lecture will be able to:
Compute the
force exerted by water on a wall due to hydrostatic pressure.
34.1
Objective
Our objective is to derive formulas which give the force water exerts on
a surface at various depths.
34.2
.
Force exerted by a fluid on a plate
– Suppose a plate of area
A
is submerged
horizontally under water at a depth of
d
meters.
Then the water directly above it has volume
V
=
Ad
.
Given that the uniform density
of water
ρ
=
m
/
V
we can deduce that the force
F
exerted on the plate from above is
F
=
mg
= (
ρ
V
)
g
=
ρ
gAd
For example, if a plate of area = 1 cm
2
= 0.000001 m
2
is at a depth of 1 m under
water, the force exerted by the water on the plate is
F
= 1000
kg/m
3
×
9.81
N/kg
×
1
m
×
0.000001
m
2
= 0.00981N.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '11
 RobertAndre
 Calculus, Fluid Mechanics, Hydrostatic Pressure, 4 m, 3 m

Click to edit the document details