Question

He starter motor of a car engine draws a current of 170 AA from the battery. The copper wire to the motor is 6.00 mmmm in diameter and 1.2 m long. The starter motor runs for 0.760 ss until the car engine

A)How much charge passes through the starter motor? (C)
B)How far does an electron travel along the wire while the starter motor is on?(mm)

Answer 1

The charge passing through the starter motor is 129.2 C, and the electron travels approximately 2.28 × 10^8 meters along the wire.

Step-by-step explanation:

A) To find the charge passing through the starter motor, we need to use the equation:

Q = I × t

Where Q is the charge in coulombs, I is the current in amperes, and t is the time in seconds. In this case, the current is 170 A and the time is 0.760 s, so we can calculate:

Q = 170 A × 0.760 s = 129.2 C

Therefore, the charge passing through the starter motor is 129.2 coulombs.

B) To find the distance traveled by an electron along the wire, we can use the formula:

d = v × t

Where d is the distance in meters, v is the velocity in meters per second, and t is the time in seconds. Since the electron travels at the speed of light, which is approximately 3 × 10^8 m/s, we can calculate:

d = 3 × 10^8 m/s × 0.760 s = 2.28 × 10^8 m

Therefore, the electron travels approximately 2.28 × 10^8 meters along the wire.

Answer 2

129.2 C

0.33758239177 mm

Step-by-step explanation:

n = Number density =
`8.46* 10^(28)\ electrons/m^3`

i = Current = 170 A

t = Time taken = 0.76 s

d = Diameter = 6 mm

Charge is given by

`q=it\\\Rightarrow q=170* 0.76\\\Rightarrow q=129.2\ C`

The charge passing throught the motor is 129.2 C

Current density

`J=(i)/(A)\\\Rightarrow J=(170)/((\pi)/(4)* (6* 10^(-3))^2)\\\Rightarrow J=6012520.07236\ A/m^2`

Drift velocity is given by

`v_d=(J)/(ne)\\\Rightarrow v_d=(6012520.07236)/(8.46* 10^(28)* 1.6* 10^(-19))\\\Rightarrow v_d=0.000444187357592\ m/s`

Distance traveled

`s=v_dt\\\Rightarrow s=0.000444187357592* 0.76\\\Rightarrow s=0.00033758239177\ m=0.33758239177\ mm`

The electron traveled 0.33758239177 mm