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Physics
Charge motion in a uniform electric field
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Launch test particles between parallel plates and compare their paths, velocities and electric work.
↓E: 250 V/mDensity follows |E| · F/v show direction
TravelledPredictedDrag launch point and v₀ handle
U = Vtop − Vbottom. U > 0 means the field points down.
Mass and geometry
e = 1.602 × 10⁻¹⁹ C; mₑ = 9.109 × 10⁻³¹ kg. 1 Mm/s = 10⁶ m/s.
Launch to watch motion. Drag the launch point or v₀ handle to aim.
Changing conditions starts a new trial and keeps the reference path.
Ready to launch
Deflection Δy
0 cm
- Time
- 0 ns
- Speed
- 5 Mm/s
- vₓ / vᵧ
- 5 / 0 Mm/s
- Eᵧ at particle
- -250 V/m
- Electric force Fᵧ
- -0.04 fN
q > 0: force points along E. Only vᵧ changes; vₓ is constant. Paths do not necessarily follow field lines.
- Kinetic energy K
- 71.07 eV
- Energy change ΔK
- 0 eV
- Electric work W
- 0 eV
ΔK = Welectric
vᵧ = 0 here. The electric force still changes vᵧ; kinetic energy is minimal during the motion between the plates.
Calculated from the model
Keep a path, then change one parameter to compare its effect.
Model notes
- Ideal test particles in a vacuum: charge in elementary charges e and mass in electron masses mₑ. Custom combinations need not represent real particles. Particle size is exaggerated.
- Uniform field between plates: Eᵧ = −U/d, with U = Vtop − Vbottom and y upward. Fringing fields are neglected; beyond the edge motion is straight and uniform. This kinematic approximation does not describe the full field of a finite capacitor.
- Nonrelativistic mechanics; speeds below 0.05c in the control range. Gravity, magnetic fields, radiation, particle interactions and their effect on the applied field are neglected.
- Impact readings describe the instant just before contact. Rebounds and energy transfer to a plate are not modelled. Work accumulates inside the field and stays fixed after exit: ΔK = Welectric. No global potential energy is assigned to the abruptly truncated field.
- 1× playback represents 20 ns per real second. Vectors show direction; different vector types do not share a length scale. Observation ends at the screen, viewing boundary or 200 ns.