The starter motor of a car engine draws a current of 170 a from the battery. the copper wire to the motor is 4.60 mm in diameter and 1.2 m long. the starter motor runs for 0.930 s until the car engine starts how much charge passes through the starter motor?

The charge that passes through the starter motor is .

Explanation:

Known Data

First Step: Find the number of the electrons per unit of volume in the wire

We use the formula .

Second Step: Find the drag velocity

We can use the following formula

Finally, we use the formula .

the amount of current in the coil

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.