# Another Current and Drift Velocity Question

• predentalgirl1
In summary, the conversation discusses the calculation of the number of electrons that pass through a given location in a circuit during a 1.5 second startup time, when a car's starter motor draws 50 A from the battery. One method calculates the number of electrons as 4.69x10^20, while the other method calculates it as 1.56x10^21. The first method is considered correct, as the second method's equation and numbers are unclear.
predentalgirl1
[SOLVED] Another Current and Drift Velocity Question

1. A car's starter motor draws 50 A from the car's battery during startup. If the startup time is 1.5 s, how many electrons pass a given location in the circuit during that time?

3.As current = rate of flow of charge,
I = q/t
Charge, q = I.t = 50 x 1.5 = 75 C
1 electron has charge, e = 1.6x10^-19 C
And q = N.e
Number of electrons which pass in 1.5 s,

N = q/e = 75 C/1.6x10^-19 C = 4.69x10^20 electrons

OR use this equation:I = ne/dt and get:

n = 50 x 5 = 250
e 1.6 x 10-19
= 156.25 x 10^19
= 1.56 x 10^21 electrons
1.56 x 10^21 electrons pass during that time.

It would be better if you used units. I'm not sure I understand your numbers.

In the second equation, what is the 5 in n=50 x 5?

The first method is correct. I'm afraid I don't understand the second one. What's "d" in that equation?

## 1. What is another current and drift velocity question?

Another current and drift velocity question typically refers to a question about the movement of charged particles in a conductor, such as a wire. It involves understanding the relationship between current, which is the flow of charge, and drift velocity, which is the average speed at which the charged particles move.

## 2. How are current and drift velocity related?

Current and drift velocity are directly proportional to each other. This means that as the current increases, the drift velocity also increases. Conversely, as the current decreases, the drift velocity decreases.

## 3. What factors affect drift velocity?

The drift velocity of charged particles in a conductor is affected by several factors, including the material of the conductor, the cross-sectional area of the conductor, and the strength of the electric field applied to the conductor.

## 4. What is the formula for calculating drift velocity?

The formula for calculating drift velocity is v = I/neA, where v is the drift velocity, I is the current, n is the number of charge carriers per unit volume, e is the charge of each carrier, and A is the cross-sectional area of the conductor.

## 5. How does temperature affect drift velocity?

Temperature can affect the drift velocity of charged particles in a conductor. In general, as the temperature increases, the average speed of the particles also increases, leading to a higher drift velocity. This is due to the increased thermal energy, which causes the particles to vibrate more and move faster.

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