Motion in a uniform electric field

Repair the common break

Common misconception: A charged particle always moves along an electric field line.

Correct model: The field sets acceleration through F = QE; velocity and acceleration together determine the trajectory.

Worked transfer

Between uniform plates, a positive charge has acceleration QE/m along E. If it enters with transverse velocity, that velocity persists while the field adds perpendicular acceleration, producing a parabola.

Guided practice

Explain why “A charged particle always moves along an electric field line.” fails. Then construct one example that correctly applies motion in a uniform electric field.

Independent practice

An electron enters a uniform downward electric field with horizontal velocity. State its acceleration direction and describe its path, with justification.

Return to the recorded repair plan when the explanation and application are secure enough to re-test.