Answer:
t=13.49 min
Explanation:
Given that
I=300 A
A= 0.21 cm²
L= 0.85 m
Number of charge carriers per unit volume = 8.49 x 10²⁸ m⁻³.
We know speed of the electron given as
V=J/ne
J= I/A
So
V=I/neA
[tex]V=\dfrac{300}{8.49\times 10^{28}\times 1.6\times 10^{-19}\times 0.21\times 10^{-4} }[/tex]
V=0.00105 m/s
lets take t is the time when electron travels from car battery to the starting motor
t = L/V
[tex]t=\dfrac{0.85}{0.00105}[/tex]
t=809.52 s
t=13.49 min
