# Search results for query: *

1. ### Voltage around a loop, half inside a capacitor and half outside

Homework Statement This is not a homework problem, I'm working through griffiths Electrodynamics on my own. Homework Equations when there is an emf source, since electrosatic fields integrate to zero around a loop The Attempt at a Solution The solution claims that since the integral of f...
2. ### Why Centrifugal Force in the Derivation of Curvature Drift

Homework Statement This is a question about a pretty basic plasma physics derivation. In the standard derivation of the Curvature Drift of a charged particle in a magnetic field with curvature, the force that they use is the "imaginary" centrifugal force (or the force the guiding center sees in...
3. ### I How are Bamboo Copter Toys Stabilized?

This is a Bamboo Copter: https://en.wikipedia.org/wiki/Bamboo-copter So the key to building a stable one is that the "rod" part spun by the hand has to be heavy. However, a uniform force field cannot exert a torque on a rigid body. By elimination, I assume that external forces stabilize the...
4. ### Derivation of EoM for two interconnected rigid bodies

I set a small project for myself to design a controller for a rocket, which moves a mass around to shift the center of mass, in order to steer a rocket. The picture shows a simplified model of a rocket plus a movable mass. , shown is a rod for the rocket, and a mass for the controller. there...
5. ### Steering rockets in space by shifting CM

So, I'm investigating a certain way of steering a rocket in space for my first undergraduate research project. Essentially, the idea is to control the location of some mass located on a horizontal track perpendicular to a rocket, so that when the mass is moved, the center of mass of the rocket...
6. ### I Building intuition for Quantum Mechanics

I've been reading about self teaching physics (mainly because the college curriculum is too slow to get me to any meaningful level of understanding at the end of four years), and an issue was brought up about lack of intuition in quantum mechanics/GR, and depending too much on the math. I was...
7. ### On the logical-ness of the principle of superposition

Wow necroing a two eyar post. I was just asking why it is not a "logical" next step to assume that the coulomb or gtavitational forces add linearly just from an experiment with two particles. Ie, if you bring in one charge from infinity, you find some sort of 1/r^2 dependenced but you know...
8. ### Schools How to allocate time/how to prep for grad school

thanks for the encouraging words. As I am. I am taking Signals and Systems this quarter but the professor is somewhat mediocre, so I'm watching the series by Oppenheim while working along that textbook instead. It's rather unfortunate, however, that my school splits the topic into continuous...
9. ### Schools How to allocate time/how to prep for grad school

I will keep this in mind when the time comes. And as I'm looking for research. Thanks.
10. ### Schools How to allocate time/how to prep for grad school

Ah yes, my faculty mentor said I'd be interested in such a major, but turns out my school doesn't offer the major. I just got to make do with what I have haha.
11. ### Schools How to allocate time/how to prep for grad school

I meant that more as a offhanded joke. I'm taking a four class quarter right now and it seems fine. I have enough time left for clubs, and ballroom dancing on the weekends. I have a spreadsheet for tracking classes that I plan to take, and it already includes the EE classes that I don't need to...
12. ### Schools How to allocate time/how to prep for grad school

If you meant this figuratively, then I could complain about how I have no time left after studying. Logistically, at UCLA to complete an EE degree you have to take 4 classes per quarter (3 classes for 2 quarters). I came in with 5 math classes fulfilled, taking two physics labs over the summer...
13. ### Schools How to allocate time/how to prep for grad school

Clarification: I'm completing my EE major in four years, I just have a rather large amount of left over class space, with which i can either choose to rush to grad school, or taking additional classes. 1) regarding physics: I've found that being good in physics translates to mathematical...
14. ### Schools How to allocate time/how to prep for grad school

Feel free to skip to bottom to read the questions. Below is some relevant background. I'm currently an undergraduate freshman in EE. I find physics exciting (not sure if I like it because I'm good at it, or I'm good at it because I like it), so I'll be taking most of the courses that a physics...
15. ### I Processes that determine the color of fire

Thanks for all the replies, I'll be taking optics/electrodynamics/thermodynamics courses in the three coming quarters, I'll set a reminder to come back to this in a year :D. I do have a general idea of what both of you are saying, but it seems like I'd appreciate many of the basic ideas you are...
16. ### I Processes that determine the color of fire

I never really had a good idea of the mechanisms behind color. why we feel heat, what determines the color of fire, etc. So, today I sat down and did some research. I want to explain the processes here to make sure I got it completely right: For complete combustion of most hydrocarbons (blue...
17. ### Intuition for why escape velocity doesn't depend on angle

I see. that helps me interpret my math more clearly, thanks.
18. ### Intuition for why escape velocity doesn't depend on angle

Oh I see, it's double that of a mass in circular orbit. makes sense, thanks.
19. ### Intuition for why escape velocity doesn't depend on angle

v vanishes, but isn't that the same end behavior as a mass launched at escape velocity? it vanishes as r - > infinite?
20. ### Intuition for why escape velocity doesn't depend on angle

KE= (m*Re^2*g) /(2*r) I'm not sure what this implies, though.
21. ### Intuition for why escape velocity doesn't depend on angle

Homework Statement solve for escape velocity from Earth's surface Homework Equations just either use the line integral, and the tangential term disappears, or just use the energy equations The Attempt at a Solution I've solved it, but I'm having some trouble just coming to grips with this...
22. ### I Self balancing stick based on flywheels

ah yes I understand now. thanks.
23. ### I Self balancing stick based on flywheels

Sorry, I was confusing it with the cubli, which minimizes the flywheel velocities so that gyroscopic effects are negligible. I was wondering, if you stopped just short of the motor reaching max rotational speed, would there be a way to "reset" the default rotational speed back to zero, or are...
24. ### I Self balancing stick based on flywheels

that was not what I asked. my question is about how a restoring torque is limited by how long the motor can speed up for. what I mean is, the flywheel can only general a restoring torque through ACCELERATION, what this implies, is if you need to generate a constant restoring force, you need to...

26. ### I Self balancing stick based on flywheels

so I recently saw a video where a stick had two flywheels attached on the top, they would accelerate or decelerate based on the pitch of the stick. my question= if you delivered enough impulse do the stick, would the stick stop being able to balance? since the restoring torque is based on...
27. ### Interactive Holograms in Iron Man

I assume most people know what I'm talking about. I've done some mild googling regarding hologram technology, but currently technology isn't nearly as robust as what Stark has in the movies, and I'm not so interested in that aspect anyways. How would you set up a room so that you can interact...
28. ### Programs Tell me (EE major) some reasons to take more physics classes

My situation: I am an EE major, first year, 6 quarters ahead in math (meaning i have 6 "extra" slots for electives). I will probably take many CS courses, or maybe switch into a combined CS and EE major (like ECE or CSE), partially due to interest and necessity of coding skills nowadays. I also...
29. ### Studying Necessity of formal math education for Electrical Engineer?

So, I am majoring in Electrical engineering, and probably doing a decent amount of Physics and Computer science courses until I can no longer squeeze it into my schedule. In the far future, I definitely plan to work in industry, and hopefully in R&D type engineering work. Will I ever in my...
30. ### B How to track the center of mass of a human in a video

So a few months or years ago I learned that most of the energy from swinging comes from raising the center of mass at the lowest point of a swing. I also recently found a method of swinging that maximizes this energy gain. You squat on the swing, and stand up every time it gets to the lowest...
31. ### Calculus Reviewing Multivariable calculus to skip in college

Hi, I'm asking for a friend who will be majoring in chemical engineering. We have already taken Calculus I, II, and III under a course offered by a local community college. Admittedly, it was taught from stewart's series of calculus books, and we did exactly zero proofs in the class, and all...
32. ### B Viability of log-log transformation for some data

I have taken AP Statistics, and this is for the final project. What we have learned consists of some simple significant tests (t test, z test for proportions, two sample tests, chi squared, and logarithmic transforms). My partner and I are considering creating a scatter plot of distance between...

34. ### B Dimension of subset containing two circles

Clarification: I meant just the two curves. Not the space in between, but I see from your explanation that it is one dimensional. Thanks.
35. ### B Dimension of subset containing two circles

So I am reading a calculus book, and went online to find explanations for why a circle is 1D. Theres the explanations that say something about zooming in very close and seeing that it's indistinguishable from a Real line. Or you can specify any point on it with only one variable Or if there was...
36. ### How to measure the output of a generator

Some clarifications: We are using a box fan as the wind source. The blades will only sweep out a circle with a 15 inch diameter. (it was even smaller in science olympiad, so this feels rather liberating) Yes, we won't be trying to use this to produce usable electricity. We are varying the...
37. ### How to measure the output of a generator

I am doing a math project. Our goal is to use Mathematica to design some small wind turbine blades, 3D print them, and then attaching it to a small dc motor. I did something very similar for science Olympiad, where we had been measuring the "power" by measuring the voltage between the two wires...
38. ### Can Vibrating Shoes Help Us Walk on Water?

Would shoes that vibrate very quickly enable us to walk on water? Why or why not?
39. ### I Two sheets of glass stick together. Why?

but going back to the original question, the two most relevant forces are then just adhesion (much smaller), and air pressure, right?
40. ### I Two sheets of glass stick together. Why?

I think i recall approximately that the force of an infinite charged plane on a charge L away from the plane is the same as the force of a sphere of radius L/2 on the point, if the point is right on the surface of the sphere. It should be trivial to extend this to mass, since the gravity and...
41. ### I Two sheets of glass stick together. Why?

When the sheets are very smooth and are pressed together strongly, I guess they could be viewed somewhat as a unit, so the force to pull them apart would be approximately equal to or less than the atmospheric pressure times the area of the sheets, but definitely not more than, is this correct...
42. ### Constructing a graph of WiFi strength

Wow thanks for all the input, once my college applications are done I'll probably dabble a bit in Java and Android app developer and get started on the project.
43. ### Constructing a graph of WiFi strength

I have way too much time to spare, so I came up with this fun little project. What i want to do is use my phone or laptop to incrementally collect data on WiFi strength at my location at that time, using GPS (longitude and latitude), and once I have enough data, (I'm fine if it takes like...
44. ### Soda bubble formation rate on plastic straw and glass cup

Something i found while doing research, they state that PET has a specific property to absorb bubbles, but why? Plastic straws have a specific property to adsorb bubbles. This property is more significant in PET (poly ethylene terephthalate) and hence these bottles serve as good containers to...
45. ### Soda bubble formation rate on plastic straw and glass cup

I observed that if you pour soda into a glass cup and leave the straw inside, bubbles seem to form on the plastic cup at a much much quicker rate. Why is this? Why do bubbles form on the straw at all? Not sure if this should be in general physics or chemistry
46. ### B Trash can fire tornado

but also, the fire tends to get much bigger once it starts spinning, why is that?
47. ### B Trash can fire tornado

Why does this happen? When the trash can is not moving, the air gets drawn in through the mesh and flows more or less straight to the fire. I'm thinking that a rotating trashcan "pushes" the wind in the direction that it's rotating, so that the wind no longer blows towards the fire, but...
48. ### Programs Physics minor or physics major

Perhaps you might consider that I'm not taking it to get better at ee, but rather for interest or knowledge? The lead researcher at my dad's company that makes ultrasound oceanography devices took a lot of physics classes and says it's been useful very frequently
49. ### Why the temperature of a moving jar of gas doesn't increase

Ah thanks, makes much more sense than my friends explanation haha
50. ### Why the temperature of a moving jar of gas doesn't increase

The frame in which the average velocity is zero, so the jar.