- Due tomorrow Tues 1.14.14
- Electric Field Maps
- Colorized
- observations
- interpretations
- Post Lab Question "Click Here"
- on a separate piece of printer paper NDPS
- Print or sketch the picture/question
- answer the questions
- http://groups.physics.northwestern.edu/lab/DOWNLOAD/equipotential.pdf
Need Ideas
Infographics
Assignments:
Fileds Potential Work
When there are two opposite charges, and we are drawing the field lines, how does the line extending straight out the back of the positive charge end up at the negative charge?
ReplyDelete-Kevin Meglathery
I brought a kit home and ran into a problem: both nails have circles around them of high numbers like 6 and 7 while the experiment I did in school had that on one side and the smaller numbers on the other. Switching wires and +/- did not help either.
ReplyDeleteDid you attach both wires to the positive end of the battery? That might be causing both nails to emit a high voltage.
DeleteIf you take a different battery, you could test it to see if the meter itself is not working.
Or you can refer to the Physics Rulebook pages 1 through 1,000; check your connections.
-Kevin Meglathery
No one was connected to + and the other -, and one nail had 0 and the other had close to 9. I used the same meter in school and it was working fine.
DeleteWere the pins completely pushed into the paper? My group had a probably with that; the pins weren't completely touching the silver part and we were getting high readings around both.
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DeleteThat fixed it thanks John
DeleteWhat does NDPS stand for?
ReplyDeleteI agree with Noah
DeleteName, date, period, and I guess subject.
Delete-Kevin Meglathery
Where should we put the observations and interpretations?
ReplyDeleteI would guess either right on the map or just a separate piece of paper. Maybe it can just be in your notebook and he just wants to have a discussion in class about it.
Delete-Kevin Meglathery
How do we do letters D. E. and F. on the post lab questions?
ReplyDeleteI'm pretty sure that D. is just asking for the difference in voltages.
DeleteI'm not completely sure if I am doing the next two correctly, so please tell me if I am wrong so I can fix it.
To find the strength of the electric field in E, use the equation E=delta V over delta D. This will give you an answer in volts/meter which is equivalent to Newtons/coulomb. Multiply this answer by the value of the charge (to cancel the coulomb unit) and divide by the distance between the points again (because work equals Newtons/meter).
For F, you need to think about whether or not moving the charge along a different route will make any difference. If it does, then try to find out how much.
Once again, this is not guaranteed to work. It makes sense to me, but I may be misinterpreting something.
-Kevin Meglathery
Correction; multiply by the distance in the 7th line of the post, do not divide. I thought it was a Newton/meter instead of a Newtonmeter. A big thank you to John for noticing.
Delete-Kevin Meglathery
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DeleteVery nice synopsis Kevin. You will be a great professor one day. I was just going to say that work is Newton meters instead of newtons per meter, but you beat me to it. Otherwise, I agree with what you said.
DeleteWhat are we supposed to use for change in distance to find magnitude of the electric field?
ReplyDeleteThere's a small key at the bottom left of the diagram
DeleteThe maximum voltage I can get without touching the pin is only 5.6 did anybody else experience a similar problem and if so how was it resolved?
ReplyDeleteFor the electrostatic problem, I got an answer of 1.125*10^-6 N.
ReplyDeleteI found the force exerted on Q3 by each of the other charges then used Pythagorean Theorem to add them.
-Kevin Meglathery
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DeleteI used the same method
DeleteI got a different answer for magnitude of the net electric force exerted on Q3. First off, my answer was in N/C. I ended up with 1.12x10^-10 N/C.
DeleteDid you remember to convert from centimeters to meters? I didn't at first until I realized my answer was too small. How can you start with 10^-9 and increase it to 10^-10?
DeleteIn regards to units, the unit for the k constant is Newtons*meters squared over coulombs squared, so everything will cancel except the Newtons.
-Kevin Meglathery
Your right. I didn't convert, and I forgot the magnitude of a force was newtons.
DeleteIn urgent need of help--can only find voltages between 5.3 and 3.7 on the map with the two bars. All connections are good, the battery's voltage is good, idk what is wrong.
ReplyDeletenvmd, the placement of the pins was wrong; they were not touching the metallic paint, they were in the same place as in the other map
DeleteBoth above from Noah Lee
DeleteThat was a given
DeleteDoes anyone know how to use e0 (permittivity of free space) for Gauss' Law? The book said it was a constant.
ReplyDeleteNot entirely sure, John, but we don't need to know Gauss' Law for this quiz today.
ReplyDelete