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

freezing

deposition

condensation

explanation;

melting also called fusion is the process where solid becomes liquid, sublimation is the process where solid becomes gaseous without first changing to liquid, deposition involves change from gaseous to solid state, freezing involves change from liquid to solid, boiling or evaporation involves change of liquid to gaseous state, while condensation is the change from gaseous state to liquid state.

endothermic reactions involves absorption of heat from the surroundings or the environment while exothermic reactions involves loss of heat energy to the surroundings.

in this case, sublimation, evaporation and melting are endothermic reactions (gain energy from the environment) while, freezing, deposition and condensation are exothermic (loss of energy to the surroundings) reactions.

force is based upon mass and acceleration.the statement is not always true.

it can be explained from newton's second law of motion.

as per newton's second law of motion the rate of change of momentum is directly proportional to the applied force and takes place along the direction of force.

mathematically it can be written as -

                                              ⇒      

here   k is the proportionality constant whose value is 1.

                                                            [a is the acceleration=dv/dt]

hence we see that force not only depends on mass and acceleration but also on velocity and rate of change of mass. force f will depend on mass and acceleration only when mass is constant.

hence the statement that force is based upon mass and acceleration is false.