Name Lab 1 Coulomb's law Date This activity consists of two Parts Part one: Eclectic force versus distance. Part two: Electric forces versus charge. To be familiar with the electrostatic force magnitude direction and the parameters affect this force using Phet simulation open the following link and play with it. https://phet.colorado.edu/sims/html/coulombs-law/latest/coulombs-law_en.html Objectives: 1-Satisfy Coulomb's law experimentally 2-Study the parameters that affect the electric force. (distance and charge) 3-Find experimentally the electric constant k Theoretical Background: Coulomb's Law: "The magnitude of the electric force that a particle exerts on another is directly proportional to the product of their charges and inversely proportional to the square of the distance between them." Mathematically, the magnitude of this electrostatic force FE acting on two charged particles (q1,q2) is expressed as: FE = k q1q2/r2 Where r is the separation distance between the charged objects and k is a constant of proportionality, called the Coulomb constant, k = 9.0 109Nm/C. Part one: To satisfy the objectives do the following steps. 1-Click on the following link and fix the charge qland q2 write their values in the table 1. https://phet.colorado.edu/sims/html/coulombs-law/latest/coulombs-law_en.html 2-Change the distance between the two charges as shown in the table 1. 3-Record the force value for each distance. 4-Fill table 1 by finding rand 1/r., 1 3-Calculate the percentage error in k (known =9.0 10Nm/C) Note: Attach the graphs to your sheet Part two: 1-Uses excel software and plot a graph relates F and Q2 (C). comments on the graph. 2-Use the graph to find the electric constant k. 3-Calculate the percentage error in k (known =9.0 10Nm/C) Note: Attach the graphs to your sheet Tablel: r(cm) 10 9 8 7 6 5 4 3 Q2-10C Q = 5C 1/r (m) F (N) 2 (m) Part two: To satisfy the objectives do the following steps. 1-Click on the following link and fix the charge q1 and the distance r, write their values in the table 1. https://phet.colorado.edu/sims/html/coulombs-law/latest/coulombs-law_en.html 2-Control Q and fix it at 4c and fix the distance between the two objects at 5 cm, as record them in table 2. 3-Change the charge of object 2 as shown in the table 2 and for each q2 record the electric force between the two objects in table 2 Table 2: For Q= 4c and r= 5 cm Q2 () 2 Q2 (C) F(N) 3 4 5 6 7 8 9 10 Data Analysis Part one: 1-Plot a graph relates F and r. comments on the graph. 2-Plot one more graph relates F and 1/r2. Use the graph to find the electric constant k.