How long does it take electrons to get from a car battery to the starting motor? assume the current is 260 a and the electrons travel through a copper wire with cross-sectional area 0.200 cm2 and length 1.00 m. the number of charge carriers per unit volume is 8.49 × 1028 m-3.

17.41 minutes

Explanation:

i = 260 A

A = 0.2 cm^2 = 0.2 x 10^-4 m^2

l = 1 m

n = 8.49 x 10^28 per cubic meter

Let the drift velocity is vd.

The relation between the current and the drift velocity os given by

i = n e A vd

260 = 8.49 x 10^28 x 1.6 x 10^-19 x 0.2 x 10^-4 x vd

vd = 9.57 x 10^-4 m/s

Let the time taken be t

time = distance / speed

t = l / vd = 1 / (9.57 x 10^-4) = 1044.93 seconds = 17.41 minutes

second mirror gathers light from a faraway object and reflects it to another mirror. - a.

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.