# Search results

1. ### Linear Dependence

Err, it was part of: 1, cos(pi x), sin(pi x). Those are the functions. 1 is linear independent, cos(pi x) and sin(pi x) I'm not sure about.
2. ### Linear Dependence

The question is: Check the linear dependency of the functions sin(pi x).
3. ### Linear Dependence

Check for Linear Dependence for: \sin \pi x [-1, 1] I'm thinking it's Linear Dependent. Since it says that any linear combination must be 0. a*x + b*y = 0, a = b = 0. So for any integer x, the value is 0. So [-1, 1] works.
4. ### At a crossroad; Civil or Mechanical Engineering

Well, I'm going to a big University this upcoming fall. I'm at a crossroads on what and where I want to go in terms of Engineering. I'm planning to shoot for my masters. Civil vs Mechanical. I'm a bit sad that Civil Engineers get paid crap and it takes so long to get paid well (not sure?)...
5. ### Slightly Confused About Tension

The best thing to do is draw a force body diagram (as said above by Archduke). It makes it a lot easier. The forces you see in the X or Y need to all equal out to M*A. Since Fx or Fy = M*A, also the sum of forces must equal m*a. So in the picture, you have the force of gravity pulling down and...
6. ### Work example wrong in my text? (it's driving me bonkers!)

Calling the X and Y on the diagonals; there is no acceleration in the Y. http://img87.imageshack.us/img87/6626/problemzl2.th.jpg [Broken]
7. ### Work example wrong in my text? (it's driving me bonkers!)

\ is the Y, / is the x. There is no acceleration in the Y, as this object is fixed on the ramp. If it had acceleration in the Y, it would be moving up or down. However, it is not. Through similar triangles, the {Fy = N = mgcos(theta).
8. ### Work example wrong in my text? (it's driving me bonkers!)

Through similar triangles. {Fx = mgsin(theta) = ma {Fy = N - Wcos(theta) = 0 (no accel in the y); N= Wcos(theta). The theta is 10 degrees.
9. ### Work example wrong in my text? (it's driving me bonkers!)

Horizontal distance from top to bottom; refers to the distance that the object travels on the incline. Rather than the bottom of the triangle. The actual distance it travels is 40m, however, we want the height. So we just do the cos(theta) of it, cos(theta) = adjacent/hypotenuse. adjacent =...
10. ### Work example wrong in my text? (it's driving me bonkers!)

No, you use the inclination of the hill =p. The work book is correct. d*cos(theta) = height. mgh -> (45)(-9.8)*[0-40cos(10)] = 1.7x10^4 J (two sig figs)
11. ### Two Resistance Problems (Circuits)

Doh! Haha, that could be the problem =p. It helps to read carefully :s.
12. ### Two Resistance Problems (Circuits)

Homework Statement 15. (II) A close inspection of an electrical circuit reveals that a 480-Ω resistor was inadvertently soldered in the place where a 320-Ω resistor is needed. How can this be fixed without removing anything from the existing circuit? 16. (II) Two resistors when connected in...
13. ### Forces and Speed

We were talking about, let's say we were to do things in incredible slow motion. We had two magnets doing something (attracting/repelling), the magnetic force is there. We were to destroy a magnetic instantaneously. Does that force act instantaneously or does it take time? I haven't gone...
14. ### Forces and Speed

Okay, so forces don't have speed but a force acting on a body have speed? Still kind of confused. Basically, does the force of gravity have speed or does gravity have speed?
15. ### Forces and Speed

Just speed as a magnitude; forces don't have speed correct? I was trying to explain something to a friend, and it was very hard for me to express or explain in English. He had to drop Physics after classical mechanics. So it's very difficult arguing with him. We got on the subject of gravity...
16. ### Force on a Charged Object in a Field

Okay, first of all draw a picture of the forces acting on it. Get a grip or an idea of how it's happening. It's a lot easier to really see these problems when you can see how it's happening. Remember when you did vectors a long time ago in Physics =p. Same ideas apply. Remember also, F = qE.
17. ### Electricity through wires

Indeed, in Chemistry and even in Physics it's well known. However, the Chemistry model in Quantum Mechanics really explains it well. Water is an alright model to compare it to, but that breaks down real quick.
18. ### A few fundamental questions I'm having trouble on

The why of things is a difficult subject. There's a billion of wrong and right answers; all rhetorical of course =p. Hehe, but it's interesting with forces =). Why do like charges repel and why doesn't gravity? Is it the very nature of this Universe?
19. ### Piece of cake

You can do it in one cut, but in two cuts here is how it goes. 1 cut, cut it in half horizontally. 2 cut, cut it in half vertically. Just switch the top pieces and you have 2 pieces with equal volumes. >_M, I should be studying for the science & engineering physics exam on Wednesday haha.
20. ### 5 Star Logic Problem (100 prisoners and a light bulb)

Uhh, the plan will be before anything the first person picked will assert that they know not everyone has gone. Thus, their assertion is correct.
21. ### Einstein's Intelligence Quiz ?

I did it in about 45 seconds in my head; I just read the first few clues and skipped the middle and read a few of the last clues heh.
22. ### Momentum of cannon ball homework

You can do it that way; however, it is a grunt method. The key thing was that it is momentum, so he/she should be learning it through momentum. Such as you could go about projectile motion in how far something will land. Set it up into the x and y vectors, say that there's no acceleration in...
23. ### Momentum of cannon ball homework

Actually as said this is a momentum problem; so need to do all that ugly stuff =p. You're already past the "grunge" way of doing the problems. It's like the idea of a ball striking another ball and both going off at different angles. This is a two dimensional collision essentially. One...
24. ### What is electromagnet?

What do you think the answers are to these? What do you feel electromagnetism is from your knowledge through research?
25. ### Somebody please explain this pic?

Same idea as a straw; I'm sure you've done this many times. Suck up some liquid or just put your straw into a liquid and then put your finger on top of it pull the straw out. Why doesn't the water just fall out of the straw. This is due to the inside and outside pressures.
26. ### Mechanical wave

Draw it out; essentially when you draw it you should setup a force body diagram on what's exactly happening on the rope. After, you will then realize why it travels in a particular direction. If you're still having troubles; make a rough sketch or something of what you think is happening with...
27. ### Can a physicist learn his math tools from wikipedia alone?

The thing that makes me a little bit peeved is when someone searches a topic on wikipedia and believes they can talk about. A lot of these people try to disprove the basic laws of physics and other things. I've seen people try to argue that these laws are wrong and incorrect. And many of you...
28. ### Civil Engineering - Structures

I was curious if anyone has this as a job/major? I'm 100% sure I'm going into it. I haven't done any job shadowing =(. I really want to, but, I personally don't know anyone who does it. For those who do it: How are the working conditions? I heard you work with a lot of people also. I was...
29. ### Can a physicist learn his math tools from wikipedia alone?

Nope. Once you get into specific areas of Physics; each his it's own separate language to go with it essentially. Such as Calculus is really the "language" of classical/general physics. But later down the road you may use tensors, you may use different things. You really can't get this from...
30. ### GPA = owned. Should I worry?

Most model schedules for Civil Engineering is to take your Calc series and Chem series together. Then physics, statics, linear algebra, differentials etc. However my colleges Modern Physics for Engineering goes in this order: Mechanics - Pressure/Waves - Elec/Mag stuff. I'm taking Physics...