Physics 30 Outcome 1 Lesson 2: Coulomb's Law Lesson 2 Practice Problems 1. In a hydrogen atom, an electron is 5.29 x 10'11 m from a proton. An electron has a charge of-1.50 x 10'\" C, and the proton's charge is +1.50 x 10'19 0. Calculate the electrostatic force of attraction acting on the two charges. [8.22 x 10'EN [attraction]] 2. The electric force between two charged objects is 5.2 x 10"' N when the objects are 3.11 x 10'1 m apart. What is the electric force between the same objects if the distance is changed to 4.04 x 10'1 m? [3.1 x 10"1 N} 3. Two small metallic spheres have the same mass and volume. One of the spheres has a charge of +4.00 [Hi and the other a charge of -1.00 [.10. lfthe two spheres are brought into brief contact with each other and are then separated to a distance of 0.200 m, what is the electric force between them? [0.505 N] 4. Three charges are placed in a line, as shown in the diagram. DON'T DO. MISSING DIAGRAM a] What is the net electrostatic force on charge A? [1.20 x 10'l N [rightl] b] What is the net electrostatic force on charge B? [2.49 x 103 N [leftll 1.0 cln 5. Calculate the net electrostatic force on charge B shown in the figure to the right. [2.54 x _2_m\"c@' $1"an 101 N [225]1 ' 9w'\\.___ um cm @- '2m \"C 5. A metal sphere with a negative charge of 3.00 mi is placed 12.0 cm from another similar metal sphere with a positive charge of 2.00 mi. The two spheres momentarily touch, and then return to their original positions. Calculate the electrostatic force acting on the two metal spheres. [1.56 I 10'1 N [repulsionll 2. A metal sphere with a charge of 2.50 x 10'9 C is 1.50 cm to the left of a second metal sphere with a charge of +1.50 3: 104' C. A third metal sphere of -1.00 x 10'9 C is situated 2.00 cm to the right ofthe second charged sphere. If all three charges form a line, determine the net electrostatic force on the second sphere. [1.16 x 10\"1 N [left]] 8. Two point charged objects produce an electric force of 0.0520 N on each other. What is the electric force if the distance between them increases three times and one of the charges is doubled? {0.0138 N} A B .100 ac % +3.00 pc 5. From the diagram to the right determine the net electrostatic . . force on C. [16.3 N at 12.60 W of 5] 0.075 In H I 10. In the diagram to the right, A has a charge of +0.30 pt, 0 has \"1' F4 00 of a charge of -0.20 pC and C has a charge of -0.20 mi. What I is the net force on A? {0.093 N [5]] III cm Iii cm . O I! ll] L'IITI F