Three electric charges are arranged on a straight line as shown in the figure. S
ID: 1406247 • Letter: T
Question
Three electric charges are arranged on a straight line as shown in the figure. Select True or False for the following statements. True: If Q1 is negative, Q2 is negative and Q3 is positive, then Q2 MUST feel a net force to the right. True: If Q1 is positive, Q2 is negative and Q3 is positive, then Q2 MIGHT feel a net force to the right. False: If Q1 is positive, Q2 is negative and Q3 is positive, then Q2 MUST feel a net force to the right. False: If Q1 is positive, Q2 is negative and Q3 is negative, then Q2 MUST feel a net force to the right. You are correct. Previous Tries In the above figure, R 1.68 m, Q1 2.20x10-6 c, Q2 -Q1 and Q3 -Q1. Calculate the total force on Q2 Give your answer with a positive number for a force directed to the right. 3.188N Use Coulomb's Law and superposition of electric forcesExplanation / Answer
Given that :
charge on q1 = 2.2 x 10-6 C
charge on q2 = -2.2 x 10-6 C
charge on q3 = -2.2 x 10-6 C
distance between two charges, r = 1.68 m
using a coulomb's law formula, F = k q1 q2 / r2
force on q2 due to charge q1 :
F12 = k q1 q2 / r2 { eq.1 }
where, k = 9 x 109 Nm2/C2
F12 = (9 x 109 Nm2/C2) (2.2 x 10-6 C) (-2.2 x 10-6 C) / (1.68 m)2
F12 = (43.56 x 10-3 Nm2) / (2.82 m2)
F12 = 15.4 x 10-3 N
F12 = - 0.015 N
And force on q2 due to charge q3 :
F32 = k q3 q2 / r2 { eq.2 }
inserting the values in eq.2,
F32 = (9 x 109 Nm2/C2) (-2.2 x 10-6 C) (-2.2 x 10-6 C) / (1.68 m)2
F32 = (43.56 x 10-3 Nm2) / (2.82 m2)
F32 = 15.4 x 10-3 N
F32 = 0.015 N
The total force on q2 which is given as ::
Fnet (on charge q2) = F32 - F12 { eq.3 }
inserting the values in eq.3,
Fnet (on charge q2) = (0.015 N) + (0.015 N)
Fnet (on charge q2) = 0.038 N