This preview shows page 1. Sign up to view the full content.
24. (a) At depth
y
the gauge pressure of the water is
p
=
ρ
gy
, where
is the density of the
water. We consider a horizontal strip of width
W
at depth
y
, with (vertical) thickness
dy
,
across the dam. Its area is
dA
=
W dy
and the force it exerts on the dam is
dF
=
p dA
=
gyW dy
. The total force of the water on the dam is
()
(
)
2
23
3
2
0
9
11
1.00 10 kg m
9.80m s
314m 35.0m
22
1.88 10 N.
D
F
gyW dy
gWD
ρρ
==
=
×
=×
³
(b) Again we consider the strip of water at depth
y
. Its moment arm for the torque it
exerts about
This is the end of the preview. Sign up
to
access the rest of the document.
 Spring '08
 Any
 Physics, Force

Click to edit the document details