Charge in an Electric Field
Fire a charged particle between two plates. Predict which way it bends, then see the parabolic path and compare shots.
Swipe the picture sideways to see all of it.
Your shots
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Show the physics
The field E between the plates points from the positive plate to the negative plate. The force on the charge is F = qE, along the field for a positive charge and against it for a negative charge. The particle keeps its horizontal speed, and it accelerates sideways with a = qE/m, so its path is a parabola, like a ball thrown sideways under gravity.
y = ½ a t2 = ½ (qE/m) (x/v)2
So the bend is bigger for more charge and a stronger field, and smaller for more mass and for more speed. Doubling the speed cuts the bend to a quarter. After the plates, the particle moves in a straight line to the screen.
The numbers are in relative units (1 q, 2 v, 3 m and so on), so you can compare shots without needing real values.
Learn more in the Moving charges in electric fields lesson.