Quiz 1 |
EVEN ANSWERS |
HYPERPHYSICS |
THIS SIMULATION will illustrate principles of Electric forces and fields; it's related to #33 and 35 below. |
DISCUSSIONS; This quiz is example driven .
READ ALL EXAMPLES ! In the following discussions, I will
also often reference corresponding example
giving you a solid hint for get shift that car out of park and
on the road. |
(CHECK YOURSELF WITH MADE UP PROBLEM1
(MP1):) (a) Assuming gravity is the only force acting on it, how far
does an electron have to be from a proton so that its acceleration is
the same as that of a free falling object at the Earth's surface. |
82. YOU CANNOT
IGNORE MUTUAL ATTRACTION OF SPHERES, WHICH INCREASES THE
ELECTRIC FIELD MAGNITUDE E BETWEEN PLATES. SOLVING THESE EQUATIONS SIMULTANEOUSLY for E gives E = 3660 N/C. If you do not take into account the mutual attraction your answer is logically smaller E = 432 N/C. |
8. (a) number of electrons = (atomic number)*
(number of moles)*(avogadro's number), where number of moles =
mass/atomic mass. |
10. See class notes 1-22 -14 about the bricks(blobs) |
22. See example 3. The 5.00 nC charge is 0.500 m to the left of the 4.00 nC charge. The middle negative charge is 0.300 m to the right of the leftmost charge. Net force is points RIGHT from Coulomb's Law since the middle charge is closer to the rightmost charge even though the magnitude of that right charge is the smaller than the leftmost charge. See example 3 for guidance though the problem is different. |
76. The two unknown charges have equal
magnitude but opposite signs; q1 is negative. |
36.
(a) See example 6. Use the Pythagorean Theorem and find the
related angle by computing the ratio of the absolute values of the y
and x components of the Field. (b) (i) The force will be opposite the
electric field at point P example 6. (ii) The force will be
opposite the force in part (i) |
34.
See examples 6 and 8. A |
33.
(a) See example 21.7 . It is reasonable to ignore gravity.
See also the SIMULATION. (c ) and
(d) use info from the above parts. |
35.
speed2 = Vx2
+ Vy2. , where the x-component of
velocity is known. And the y-component of velocity is
(eE/m)*t, where t is discussed in part (a)
of problem 33. |
MP2.
Example 7. |
47.
Example 8. The net electric field points left and has magnitude E ‘
+ 2*E*cos 53, where E’ = E = k*(5
uC)/(0.10) 2. and
uC means micro-Coulomb. |
54.
(a) Use formula (equation) 21.9 and 21.10. Note as a becomes much larger than x,
the formula becomes the equation for an infinitely long line—See
example 10. |
53.
(a) See formula 21.8. Field
points right. |
55. (a) Formula 21.11 (b) Formula 21.8 (c) Would behave like a point charge. (d) Think ! |
MP3. Two Horizontal, Infinite plane sheets of charge are separated by a distance d. The lower sheet has negative charge with uniform surface charge density -rho <0. The upper sheet has positive charge with uniform surface charge density rho > 0. What is the electric field magnitude and direction (a) above the sheet |
MP4.
Sketch the electric field lines for a disk of radius R with a uniform
surface charge density
rho.
Use what
you know about the electric
field very close to the disc
and very far from the disk to make your
sketch. |
60. See
example 14.
Evaluate on x-axis now. |
59.
(a) the torque is zero when the angle
= 0 and the angle =
180 degrees. |