An ion of net charge -2 is accelerated through a potential difference of 250 volts. What is the magnitude of the force on the ion from the electric field between the plates if the plates are 3.4 cm apart?

Explanation:

When a charge is in an electric field, it experiences a force given by

where

q is the charge

E is the strength of the electric field

The field between two parallel plates is uniform, so it can be rewritten as

where

V is the potential difference between the plates

d is the separation between the plates

So the first equation becomes

In this problem we have:

is the magnitude of the charge

V = 250 V is the potential difference between the plates

d = 3.4 cm = 0.034 m is the separation between the plates

So the magnitude of the force is

d is the correct answer

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.