# Search results

• Users: Bassa
• Order by date
1. ### Diode - Resistor Combination

Thank you very much! I will try that!
2. ### Diode - Resistor Combination

I think I get the fist part of the question, but I am stuck on getting an expression for the current in terms of voltage for the second situation where we add a resistor.
3. ### Diode - Resistor Combination

Thank you for the reply! I do know how to solve the expression for the current through the diode and invert it to get vD. My problem is that I need to get an expression of the current in terms of voltage. Since it is not linear, I am not sure how to do that. I have not used Newton's method to...
4. ### Diode - Resistor Combination

Helo, I am in an electronic course and we just started studying diodes. I am stuck on the following problem: Place a 100 ohm resistance in series with a diode, and plot current versus voltage across the series combination. I am also given the following values for the diode: n = 1, Is =...
5. ### "Shooting Method" for simulating a Particle in an Infinite Square Well

Hello! I am trying to write a program that solves the Schrodinger Equation for a particle in an infinite square well. I did a lot of research regarding the methods that could be used to accomplish this. I am writing this program in Matlab. The method I am using is called the Shooting Method. In...

Thank you!
7. ### Initial Voltage in an RC circuit with a Current Source and no Voltage Source

Thank you very much for this explanation! I really appreciate it!
8. ### Initial Voltage in an RC circuit with a Current Source and no Voltage Source

Would the current not choose the path that has a voltage drop, which is the one with the resistor?
9. ### Initial Voltage in an RC circuit with a Current Source and no Voltage Source

Thank you for the note. I changed the title of the thread.
10. ### Initial Voltage in an RC circuit with a Current Source and no Voltage Source

I think I am starting to understand where you are coming from. Initially, I thought that current would not go through the parallel piece of wire because there is no voltage drop there, but it would go to the resistor because there there is a voltage drop and the current could flow. I have always...
11. ### Initial Voltage in an RC circuit with a Current Source and no Voltage Source

So, I think that I am misunderstanding the problem. The arrow on the switch in the diagram means that the switch was closed for a long time and then it was opened at t=0s. If this is the case, then would that not mean that the capacitor was charged at t <= 0?
12. ### Initial Voltage in an RC circuit with a Current Source and no Voltage Source

Thanks you for the quick reply! Oh! I I did not think of it this way. My answer would be "No, it would not." That raises another question that might be related to a fundamental piece of information that I don't know. Current would also not flow if there was no change in voltage, which the...
13. ### Initial Voltage in an RC circuit with a Current Source and no Voltage Source

Homework Statement [/B] Derive an expression for vc(t) in the circuit of Figure P4.13 and sketch vc(t) to scale versus. I attached a screen shot of the circuit for this problem. time. Homework Equations V = IR V = V0exp(-t/tau) The Attempt at a Solution [/B] I am trying to find the...
14. ### Change of Variable With Legendre Equation

Thanks a lot!
15. ### Change of Variable With Legendre Equation

Thank you very much! Sorry for the late reply, but I had to sleep on it. It worked perfectly fine! I was inventing my own incorrect rules for calculus, and that did not work very well! P.S. I was wondering how you were able to type those derivatives very clearly. It is much more clear than...
16. ### Change of Variable With Legendre Equation

I do have that in my solution and it leads to the earlier reply I posted. It also leads to the correct first term of the right answer. Is the following correct? -csc(θ)(d/dθ)[y] = (cscθ)^2(d^2y/dθ^2)
17. ### Change of Variable With Legendre Equation

I do have that in my solution and it leads to the earlier reply I posted. It also leads to the correct first term of the right answer. Is the following correct? -csc(θ)(d/dθ)[y] = (cscθ)^2(d^2y/dθ^2)
18. ### Change of Variable With Legendre Equation

Thanks for your reply! Here is my calculation for (1-x^2)y'': (d^2y/dx^2) = (d^2y/dθ^2)(1-x^2)^(-1) = (d^2y/dθ^2)(1-(cosθ)^2)^(-1) (1-x^2)y'' = (1-(cosθ)^2)(d^2y/dθ^2)(1-(cosθ)^2)^(-1) = (d^2y/dθ^2)
19. ### Change of Variable With Legendre Equation

Thank you very much for your reply! I have spend many an hour trying to figure out where the 2 goes, but that was to to avail. I have the following: (dy/dx)=(dy/dθ)(-1/sqrt (1-x^2))=(dy/dθ)(-1)(sin(θ))^(-1) Can you please direct me to where I went wrong on the above statement? Thanks!
20. ### Change of Variable With Legendre Equation

Homework Statement [/B] Change the independent variable from x to θ by x=cosθ and show that the Legendre equation (1-x^2)(d^2y/dx^2)-2x(dy/dx)+2y=0 becomes (d^2/dθ^2)+cotθ(dy/dθ)+2y=0 2. Homework Equations The Attempt at a Solution [/B] I did get the exact form of what the equation...
21. ### Transvese Velocity of a Standing Wave

λ∂Homework Statement Aguitar string lies along the x-axis when in equilibrium. The end of the string at x=0 (the bridge of the guitar) is fixed. A sinusoidal wave with amplitude A=0.750 mm and frequency f =440 Hz, corresponding to the red curves in Fig. 15.24, travels along the string in the...
22. ### The Line of Intersection of Two Planes

Homework Statement Find a set of parametric equations for the line of intersection of the planes. 6x-3y+z=5 and -x+y+5z=5[/B] Homework Equations The cross product formula The formula for the parametric equations of a line in three dimensional space: x=x1+at, y=y1+bt, z=z1+ct Knowing the...
23. ### Angle Between Two Planes

Well, now come to think about it more intently, why can the angle between two planes not be more than 90 degrees? I could imagine many intersecting planes having an angle more than 90 degrees between them.
24. ### Angle Between Two Planes

Thank you very much for this thorough explanation!
25. ### Angle Between Two Planes

Homework Statement I am preparing for my calculus III class over the break. I came across the formula for the angle between two planes which is: cosΘ = (|a.b|)/(||a|||b||) Homework Equations cosΘ = (|a.b|)/(||a|||b||) a.b = ||a||||b||cosΘ The Attempt at a Solution I know that the dot product...
26. ### Measuring Vectors

I'm sorry, but I am still not very clear on this.
27. ### Measuring Vectors

Homework Statement This is an example problem in my calculus textbook. I don't get how they relate the position vector to the force vector. I have taken a calculus based physics course and I don't remember establishing such relationship between the position and the force vectors. Note: I have...
28. ### Heat Transfer of ice

Thank you very much for your help!
29. ### Heat Transfer of ice

Thanks! Is the method correct, though?
30. ### Heat Transfer of ice

Homework Statement A 6.00-kg piece of solid copper metal at an initial temperature T is placed with 2.00 kg of ice that is initially at -20.0C. The ice is in an insulated container of negligible mass and no heat is exchanged with the surroundings. After thermal equilibrium is reached, there is...
31. ### Altitude of Satellites above the Surface of the Earth

Thank you everyone for your help. You guys are amazing. I love how you don't just give us the answer, you direct us to the right path.
32. ### Altitude of Satellites above the Surface of the Earth

Sorry, I was going to write 24 hours, but I realize that I need to use the SI unit for time to save me a lot of conversions and prevent me from making mistakes. I forgot to delete it. This sounds so good at the moment. The weather is very cold where I live. Unfortunately, she lives away from...
33. ### Altitude of Satellites above the Surface of the Earth

Now, for B its period is the same as the period of the earth. This mean that the same method will apply, but I would have to use 24 86400 seconds for the period in my formula. Does that sound okay? I used a solar system mobile that my girlfriend got me so I could wrap my head around it. I wonder...
34. ### Altitude of Satellites above the Surface of the Earth

My next move is to use T=2pi(r^3/2)/sqrt(GMe) Me= mass of the earth T= period of the satellite Am I in the right direction?
35. ### Altitude of Satellites above the Surface of the Earth

I think I am going to finish part A first and then move to part B. ^-^
36. ### Altitude of Satellites above the Surface of the Earth

according to my calculations it should be 8.0 hours or 28800 seconds. This is for situation A.
37. ### Altitude of Satellites above the Surface of the Earth

Sorry for not being very clear. I meant that the satellite must have circled the Earth 1.5 times for it to satisfy the information of when it was observed the second time. When it was spotted the first time in situation A, it was not seen in the sky until 12 hours later. This means that the...
38. ### Altitude of Satellites above the Surface of the Earth

So, after completing half a period on earth, the satellite appears again. Does that mean that the satellite completed 1.5 times the period of the earth?
39. ### Altitude of Satellites above the Surface of the Earth

What indicates to us that it is not geosynchronous?
40. ### Altitude of Satellites above the Surface of the Earth

No, it would be his relative velocity to me.
41. ### Altitude of Satellites above the Surface of the Earth

A geosynchronous orbit is an orbit in which the satellite is locked over one place relative to the earth. The Earth and the satellite would have the same orbital velocity. On a second thought, I don't see a lot of evidence to support the geosynchronous orbit hypothesis. They may have fast...
42. ### Altitude of Satellites above the Surface of the Earth

Well, from the description in the problem, I thought that they were both geosynchronous satellites. If so, would not that make them have the same period? The only difference would be that one is going in the direction of the Earth's rotation and the other is going in the opposite direction.
43. ### Altitude of Satellites above the Surface of the Earth

Homework Statement A) Suppose you are on Earth's equator and observe a satellite passing directly overhead and moving from west to east in the sky. Exactly 12.0 hours later, you again observe this satellite to be directly overhead. How far above the Earth's surface is the satellite's orbit...
44. ### Vector product and vector product angles

Thanks! That clarifies a lot of things. ^-^
45. ### Vector product and vector product angles

Then how would I explain how I got the right answer?
46. ### Vector product and vector product angles

Hello! I have a problem in my calculus based physics class regarding vectors. The problem says: Vectors A and B have a scalar product -6.00 and their vector product has magnitude 9.00 what is the angle between these two vectors? Here is how I approached it: -6=|A||B|cos (theta) 9=|A||B|sin...