An electron moving parallel to a uniform electric field increases its speed from 2.0 × 107 m/s to 4.0 × 107 m/s over a distance of 2.1 cm.

what is the electric field strength?

The electric field strength is

Explanation:

Because the electric field is uniform and the electron is moving parallel to it, then the net force is constant so the acceleration (a) is constant too, that allow us to use the next kinematic equation to find the acceleration of the electron.

with v the final velocity, v0 the initial velocity and Δx the distance

With the acceleration we can apply Newton's second Law that relates acceleration and net force (F):

with m the mass of the electron ().

So, the force on the moving electron is:

Finally knowing that electric force and electric field are related with the equation

with e the charge of the electron

Using the calculated value of the force and the charge of the electron ():

that would be b i just took the test : )

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in general, areas that experience high atmospheric pressure also experience fair weather. low pressure systems can cause the formation of clouds and storms. air usually flows from areas of high pressure to areas of low pressure..