Recent content by kyang002

The electron drift speed in a gold wire is 3.0 * 10^-4. 1. What is the current density in the wire? 2. What is the current if the wire diameter is 0.50 mm? J = I / A and I = nqva What is the answer?

Measurements with microelectrodes have shown that a 0.30-nm-diameter potassium ion (K+) channel carries a current of 1.8 pA. How many potassium ions pass through if the ion channel opens for 1.0 ms? What is the current density in the ion channel? I am completely lost for this one...

A metallic wire has a diameter of 4.12 mm. When the current in the wire is 8 A, the drift velocity is 5.4*10^-5 m/s. What is the density of free electrons in the metal? I have considered a wire of cross-sectional area A, with current I. V is the drift velocity of the free charges in the...

I am also using mastering physics. It is a POS program. What school and year are you taking physics in?

I never figured it out because I was stuck on how to figure out n and q.

Q = I delta t is the equation that I found. It doesn't make sense to me. Obviously I already looked in the book and cannot figure it out, that is why I am posting on this forum. If you can please leave more helpful info on how to solve the problem instead of telling me to look in the book...

The electron drift speed in a gold wire is 3.0 * 10^-4. 1. What is the current density in the wire? 2. What is the current if the wire diameter is 0.50 mm? I am unsure of which equation to use. Q = I delta t ?? Can someone help me out?

Okay, got it. The answers are 2q, q, -3q. Am I correct?

So what is the charge of q_1, q_2, and q_3? -q/E + (-2q/E) + 3q/E = 0/E = 0 The charge of each is 0?

Measurements with microelectrodes have shown that a 0.30-nm-diameter potassium ion (K+) channel carries a current of 1.8 pA. How many potassium ions pass through if the ion channel opens for 1.0 ms? What is the current density in the ion channel? I am completely lost for this one...

Property of Electric Flux = EA cos theta? But there is no theta. Unsure of the area and of the E.

Now I understand. Thanks guys.

The SI unit is m^-3. How do I find q? Or do I even need q in this equation?

Question 4 What is the charge q_1? What is the charge q_2? What is the charge q_3? Unsure of which equation to use, and the equations that I am looking at involve integration. Φ = integral (E * dA) = EA sphere Φ = q / ε Can someone teach me how to do this problem?

I am unsure of what the equation you gave was. In my book, I was given I = nqva. Care to explain on how to do the problem?