How long does it take electrons to get from a car battery to the starting motor? Assume the current is 300 A and the electrons travel through a copper wire with cross-sectional area 0.250 cm2 and length 0.900 m. The number of charge carriers per unit volume is 8.49 × 1028 m-3.

16.98 minutes

Explanation:

We are given that

Current,I=300 A

Area, A=0.250 square cm=

Length of wire,d=0.9 m

Number of charge carriers per unit volume=

We know that

Using the formula

answer; equivalent to a one(1) horsepower motor;

air exerts forces on falling objects near earth’s surface.

explanation:

the term 'free falls' refer to object that are falling towards the earth, in a situation in which gravity is the only force acting on the object.

for an object in free fall, the acceleration is constant (g, the gravitational acceleration), and so the velocity of the object constantly increases.

for objects near earth's surface, there is always another force acting on the object: the resistance due to the air. this force is opposed to the direction of fall of the object, and it is proportional to the velocity of the object, so as the object falls down, this force increases up to a point when it balances the force of gravity, and the object continues its motion at constant velocity (called terminal velocity). since in this case gravity is not the only force acting on the object, we are not in a situation of free fall.