Lab 3: Motion in an Electric Field

In this lab you will use PhET’s simulation Electric Field Hockey to study the motion of a charged particle in the electric field produced by discrete charge distributions.

Note: Unlike previous simulations, this is not an HTML5 simulation. This means it might not work

on some browsers. Please try a different browser if the simulation does not start (after a little wait).

The path of motion of the charged puck depends on its mass (which you can change by using a

slider in the simulation), the initial conditions (the puck will always start from rest when you reset

the simulation), and the electric field. In this simulation we will produce the electric field using

point charges. The objective is to find a static charge distribution that makes the charged puck

move around the obstacle(s) and reach the goal. Static means you will not be moving the charges

that generate the electric field after you start the simulation.

1. Select the checkboxes for Trace and Field to visualize the path of motion of the charged

puck and the electric field.

2. Start with the Practice and a positively charged puck. What is the simplest solution to move

the puck and score a goal? Take a snapshot of the simulation showing that you scored a

goal. Explain the path of motion.

3. Now, select Difficulty level 1. Find a simple charge distribution that allows the puck to move

around the obstacle and into the goal. Take a snapshot of the simulation showing that you

scored a goal. Explain the path of motion. How do you need to modify your charges without

changing their positions to score a goal with a negatively charged puck? Test your

hypothesis.

4. Repeat the previous step for Difficulty levels 2 and 3 only with a positively charged puck.

Include your snapshots showing your successes (as well as a description of your failed attempts) in

the Measurements and Observations section of your report. Your explanations of the path of motion

of the puck should be included in the Data Analysis and Discussion section. Make sure you adhere to

other requirements of the lab report as well.