distributed charge density volume charge density surface charge density linear charge density
TRANSCRIPT
Distributed charge density
volume charge density
surface charge density
linear charge density
3v )meter/(Coulombs
2S )meter/(Coulombs
)meter/(CoulombsL
cosr4
dydE
2o
L
r
x
r4
dydE
2o
L
2o
L
r4
dydE
22 yxr
x
y
dyr
r
x
r4
dydE
2o
L
22 yxr x
y
dyr
a
a 22222
o
L
yx
x
yx4
dyE
22o
L
ax
a
x2
x2
Ea
lim
o
L
y
x
Z
dE
cosr2
dydE
o
s
22
o
s
yz2
zdyE
22o
s
yz
z
r2
dy
o
s
2
o
s
2E
r2E
o
L
2or4
QE
100
1
0.01
1 100 r
E
aa 2/3222
o
saa
zyx4
zdydxE
y
x
Z
-a-a
a
a
finite size square sheetuniform charge density
E
r2
o
Q
4 rE u
r2o
Q
4 r E ds u ds
x y
zr
2enc2
o
Q4 r
4 r
E ds
o
encQ
dsE
requires symmetry
electric field
charge must be ENCLOSED within surface
positive or negative charge
direction of field
o
encQ
dsE
o
s
2E
sQ senc yx2Es2E
E
yx
E
yxs
o
encQ
dsE
a
z2
2E
o
s
sa
z2Q senc
yx2Es2E
within a charged sheet a
z
yx
za-a
o
encQ
dsE
yxa
z2s
L
o
E2
LQ Lenc
E s E 2 L
o
encQ
dsE
L
He showed that brewery gas extinguished lighted wood chips. When the heavy gas, as he called it, was dissolved in water, he found that it had a very pleasant and tangy taste. He had invented soda water. Acting on a suggestion in a letter from Benjamin Franklin, he showed that hollow charged vessels contain no charge on the inside and deduced that the electric force law is inverse square.
2o
QE
4 r
0Qenc
2E s E 4 r r < a
0E arb
brc
cr2
o
2QE
4 r
QQenc
Q2Qenc
0Qenc 0E
L2
o
E
2 a
2
enc L2Q L
a
E s E 2 L a
LL
L
ab
LQ Lenc L
o
E2
b 0Qenc 0E
0 a b
o
encQ
dsE
o
v
vdv
dvv
EdsE
o
v
E
“Lately I've been wondering where the slide rules went. Back in the 1960’s, slide rules were a prime accessory for those with a quantitative bent. They were suspended from belts long before calculators. In fact, they were the personal calculation engine of choice for almost three centuries.”
The principle of the slide rule was first enumerated by E. Gunter in 1623, and in 1671, S. Partridge constructed an instrument similar to the modern slide rule. The slide rule was an indispensable tool for scientists and engineers through the 1960’s.
In 50 years, the computer you are using to view this will be landfill, but your slide rule will just be nicely broken in.
It happens elsewhere other than under the Iowa Avenue bridge
