🔖 Topics

  • Electric field
  • Motion of a point charge in an electric field
  • Electric dipoles

🎯 Objectives

  • Describe the electric field around different charge configurations
  • Calculate the electric force on a point charge due to an electric field
  • Calculate the torque on an electric dipole
  • Determine the motion of an point charge within a uniform electric field

📋 Sequence

  • Definition of electric field
  • Sketching electric field lines
  • Relation between electric field and electric force
  • Torque on an electric dipole in an electric field
  • Electric field, electric force, and kinematics

🖥️ Animations, Simulations, Activities

N/A

📝 Practice Problems

  1. What is the difference between an electric field and an electric force?

  2. A point charge of \(q = -12 \: \mu C\) is immersed in an electric field of \(\vec{E} = 1000 \hat{y} \: N/C\). What is the magnitude and direction of the force that it will feel?

  3. A charge of 10 \(\mu C\) is positioned at the origin while another charge of -30 \(\mu C\) is positioned at the point (5 cm, 0 cm). Where around the two points (if anywhere) is the net electric force on a positive point charge equal to zero?

  4. A particle with a mass of 1.1 kg and a charge of 0.5 mC starts from rest at the origin. I switch on a uniform electric field of \(\vec{E} = 10.7 \hat{x} \: N/C\) at time \(t = 0 \: s\). At what position will we find the particle after 5 seconds?

✅ Partial Solutions

  1. Refer to your class notes or textbook!
  2. 0.012 N in the \(-\hat{y}\) direction
  3. (-6.83 cm, 0 cm)
  4. 0.060795 m

📘 Connected Resources

  • Giambattista, Alan, et al. College Physics With an Integrated Approach to Forces and Kinematics. 5th ed., McGraw-Hill Education, 2020.
  • Dubson, Michael, et al. “Electric Field Hockey.” PhET, https://phet.colorado.edu/en/simulations/electric-hockey. Accessed January 23, 2024.