Force Fields
Action at a distance (across empty space)how is this
possible? This happens with gravitational force and it
happens with electrical force. Newton wrestled with this
question and never resolved itbecause he thought only of
a material connectio
If a conductor carries a non-zero net charge but is in
electrostatic equilibrium, the electric field inside it is
1.
2.
3.
4.
5.
non-zero and uniform.
non-zero and radially symmetric.
non-zero and non-symmetric
None of the above.
zero.
4/15/16
Oregon Stat
E-Field Models
There are several E-field situationscharge modelsthat
well study. One model is the net (total) field produced by
one or more discrete point charges.
The other, more general, models are the net (total) fields
produced by a variety of continu
Point charge qA (= 6e) sits at (0, 0).
Point charge qB (= +2e) sits at (d, 0).
(d > 0)
Find the total E-field caused at (2d, 0)
by these two charges.
1. [ke/2d2, 0]
2. [ke/2d2, 0]
3. ke/2d2 R 180
4. More than one of the above.
5. None of the above.
4/4/16
Quick review (this is not a clicker question today)
A 2.00-mm-diameter glass sphere has a charge of +1.00 nC.
What (steady) speed does an electron (m = 9.11 x 10-31 kg) need
in order to orbit the sphere 1.00 mm above its surface? (You may
assume that the
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CONFIRMATION
3/30/16
Oregon State University PH 213, Class #2
1
Please log in with your clicker:
To po
These are two-dimensional cross sections through
three-dimensional closed spheres and a cube. Rank
order, from largest to smallest, the electric fluxes a
to e through surfaces a to e.
A.
B.
C.
D.
E.
4/13/16
a > c > b > d > e
b = e > a = c = d
e > d > b >
Gravitational Potential Energy (a review)
Assuming a uniform local gravitational field of 9.80 m/s2, what
is the change in gravitational potential energy per kg of a 10-kg
mass when it moves from a height of 6.0 m to 13.5 m?
A.
735 J/kg
B. 73.5 J/kg
C.
73