ONLINE Lab - Coulomb's law Purpose: to study the attractive and repulsive force between electric charges. Introduction Coulomb's Law describes the magnitude of the electrostatic force that exists between two charged particles (a and b) IFabl = k 1409bl where Fab is the force exerted by particle a on particle b. The charges are q, and q), and the distance between the two charges is 7. The Coulomb constant can also be written in terms of the electric permittivity, When the two charges are alike (both positive or both negative), then the force is repulsive and directed away. When the two charges are opposite (one positive and one negative), then the force is attractive and directed towards each other. This lab looks at the dependence of the Coulomb force on charges and separation distance. It uses these dependencies to determine the electric permittivity, En- Laboratory assignment Part 1: Direction of the force vector 1. Run the "Coulomb's law" PhET simulation. 2. Select the "Macro scale" option. 3. Make sure that the "Force values" box is checked and the "Scientific notation" box is uncheck. Force Values O Scientific Notation 4. Set the left charge (q1) to -10 mC and the right charge (q2) to 10 % Charge 1 Charge 2 -10 NC 1 10 NC -10 -10 10 5. Based on the direction of the arrows above the charges, is the force attractive or repulsive? 6. Set both charges to be -10 mC. 7. Based on the direction of the arrows above the charges, is the force attractive or repulsive? 8. Set both charges to be 10 mC. 9. Based on the direction of the arrows above the charges, is the force attractive or repulsive? Part 2: Electric force's dependence on the magnitude of a charge 10. Drag the left person so that the left spherical charge is centered at 0 cm, and drag the right person so that the right spherical charge is centered at 4 cm Can 11. Change both charges (q, and q2) to be 2 % Charge 1 Charge 2 - 10 10 12. Write down the displayed force magnitude in Table I. 13. Change the value of q2 and write down the displayed force magnitudes to fill in the remainder of Table I. Table I: Magnitude of electric force by varying one charge. 91 (mc) 2 12 [mc 6 8 10 F (N)