If a metal wire carries a current of 130 mA,

how long does it take for 3.50×10
20
electrons
to pass a given cross-sectional area anywhere
along the wire? The magnitude of the charge
on an electron is 1.6 × 10
−19
C.
Answer in units of s.

That many electrons have total charge

Q = 3.5*10^20*1.6*10^-19 = 56 Coulombs

Require that I*t = 56 C
where I is the current in Amps (Coulombs per second).
I = 0.130 C/s

Solve for t.

430.7692308

To find the time it takes for the electrons to pass a given cross-sectional area, we need to use the equation:

Time (t) = Number of electrons (n) / Electron current (I)

Given information:
- Electron current (I) = 130 mA = 130 × 10^-3 A
- Number of electrons (n) = 3.50 × 10^20 electrons

First, we need to convert the electron current to units of Coulombs per second (C/s). Since 1 Ampere (A) is equal to 1 Coulomb per second (C/s), we have:

Electron current (I) = 130 × 10^-3 A = 130 × 10^-3 C/s

Now we can calculate the time it takes for the electrons to pass the cross-sectional area:

Time (t) = Number of electrons (n) / Electron current (I)
Time (t) = (3.50 × 10^20 electrons) / (130 × 10^-3 C/s)

To simplify the calculation, let's express the number of electrons in scientific notation:

Time (t) = (3.50 × 10^20 electrons) / (130 × 10^-3 C/s)
Time (t) = (3.50 / 1.30) × 10^20 electrons × s/C
Time (t) = 2.69 × 10^20 s/C

Finally, we can convert the time to seconds (s) by dividing by the charge on an electron:

Time (t) = (2.69 × 10^20 s/C) / (1.6 × 10^-19 C)
Time (t) = 1.68 × 10^39 s

Therefore, it takes approximately 1.68 × 10^39 seconds for 3.50×10^20 electrons to pass a given cross-sectional area along the wire.

To find out how long it takes for the given number of electrons to pass through a given cross-sectional area, we need to determine the time taken to pass a single electron.

Given:
Current, I = 130 mA = 130 × 10^(-3) A
Number of electrons, N = 3.50 × 10^20 electrons
Charge on an electron, q = 1.6 × 10^(-19) C

We know that current is defined as the rate of flow of charge, which can be expressed as:
I = ΔQ/Δt

Here, ΔQ represents the change in charge and Δt represents the change in time.

Rearranging the formula, we have:
Δt = ΔQ/I

Since we are given the number of electrons passing through, we can calculate the change in charge using the formula:
ΔQ = N × q

Substituting the values, we get:
ΔQ = (3.50 × 10^20) × (1.6 × 10^(-19))

Now, substituting the values of ΔQ and I into the equation for Δt, we can find the time taken for all the electrons to pass through the given cross-sectional area:
Δt = [(3.50 × 10^20) × (1.6 × 10^(-19))] / (130 × 10^(-3))

Calculating this expression will give us the time taken in seconds (s).