# Model qualitatively and quantitatively the trajectories of charged particles in electric fields

Trajectory of particle in free fall in Gravitational field

If an object is dropped (initial velocity = 0) in a Gravitational field g, then it falls with an acceleration Trajectory of particle in free fall in Electrical field

If an object is dropped (initial velocity = 0) in a Electric field E, then it falls with an acceleration Trajectory of projectile in Gravitational field

Trajectories of particles in projectile motion, in a uniform gravitational field are parabolic. (without air resistance)

Trajectory of projectile in Electrical field

Let’s see how it is in uniform electric field : • horizontal acceleration = 0
• vertical acceleration: (constant acceleration)
• These two combine to produce a parabolic trajectory for a projectile
• horizontal displacement in time: • • vertical displacement in time: • therefore: , which is the equation of a parabola

Extract from Physics Stage 6 Syllabus © 2017 NSW Education Standards Authority (NESA)