Question

# QUESTION When an electron is released from rest in a constant electric field, how does the...

QUESTION When an electron is released from rest in a constant electric field, how does the electric potential energy associated with the electron, and the kinetic energy of the electron, change with time? (Select all that apply.)
options:The electric potential energy becomes more negative.The electric potential energy becomes more positive.The kinetic energy becomes more negative.The kinetic energy stays the same.The electric potential energy stays the same.The kinetic energy becomes more positive.

Use the worked example above to help you solve this problem. A proton is released from rest at x = -2.90 cm in a constant electric field with magnitude 1.49  103 N/C, pointing in the positive x-direction.
(a) Calculate the change in potential energy when the proton reaches x = 5.34 cm.

(b) An electron is now fired in the same direction from the same position. What is its change in electric potential energy if it reaches x = 12.50 cm?

(c) If the direction of the electric field is reversed and an electron is released from rest at x = 3.40 cm, by how much has its electric potential energy changed when it reaches x = 7.10 cm?

Find the change in electric potential energy associated with the electron in part (b) as it goes on from x = 0.125 to x = -0.018 m. (Note that the electron must turn around and go back at some point. The location of the turning point is unimportant, because changes in potential energy depend only on the end points of the path.)