Electrons in a particle beam each have a kinetic energy of 3.2 x 10^-17 J.What is the magnitude of the electric field that will stop these electrons in a distance of 0.1 m? (e = 1.6 x 10^-19 C)

Question

Quizplus · Accepted Answer

The kinetic energy of each electron is given by 1/2mv², where m is the mass of the electron and v is its velocity. Since the mass of an electron is constant, we can equate the kinetic energy to the work done by an external electric field to bring the electron to a stop:
1/2mv² = eEd
where E is the magnitude of the electric field and d is the distance traveled by the electron before coming to a stop. Solving for E, we have:
E = 1/ed * (1/2mv²/e)
Substituting the given values and solving, we get:
E = 2.0 x 10³ N/C
Therefore, the answer is choice C.

Electrons in a Particle Beam Each Have a Kinetic Energy