Question
TRUE OR FALSE
If Q1 is positive, Q2 is negative and Q3 is positive, then Q2 MUST feel a net force to the right.
If Q1 is negative, Q2 is negative and Q3 is positive, then Q2 MUST feel a net force to the right.
If Q1 is positive, Q2 is negative and Q3 is positive, then Q2 MIGHT feel a net force to the right. If Q1 is positive, Q2 is negative and Q3 is negative, then Q2 MUST feel a net force to the right
In the above figure, R=1.10 m, Q1=2.07·10-6 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.
Explanation / Answer
If Q1 is negative, Q2 is negative and Q3 is positive, then Q2 MUST feel a net force to the right Given R=1.10 m Q1=2.07x10-6 C Q2=-Q1 = -2.07x10-6 C Q3=-Q1 = - 2.07x10-6 C Force on Q 2 due to Q 1 is F = K Q 1 Q 2 / R 2 Where K = Coulomb's constant = 8.99 x 10 9 N m 2 / C 2 Subsitute values we get F = 0.031835 N It is along left direction So, F = -0.031835 N Force on Q 2 due to Q 3 is F' = K Q 3 Q 2 / R 2 Where K = Coulomb's constant = 8.99 x 10 9 N m 2 / C 2 Subsitute values we get F' = 0.031835 N It is along left direction So, F' = -0.031835 N Net force on Q 2 is = F + F ' = -0.063671 N = - 2.07x10-6 C Force on Q 2 due to Q 1 is F = K Q 1 Q 2 / R 2 Where K = Coulomb's constant = 8.99 x 10 9 N m 2 / C 2 Subsitute values we get F = 0.031835 N It is along left direction So, F = -0.031835 N Force on Q 2 due to Q 3 is F' = K Q 3 Q 2 / R 2 Where K = Coulomb's constant = 8.99 x 10 9 N m 2 / C 2 Subsitute values we get F' = 0.031835 N It is along left direction So, F' = -0.031835 N Net force on Q 2 is = F + F ' = -0.063671 N Force on Q 2 due to Q 3 is F' = K Q 3 Q 2 / R 2 Where K = Coulomb's constant = 8.99 x 10 9 N m 2 / C 2 Subsitute values we get F' = 0.031835 N It is along left direction So, F' = -0.031835 N Net force on Q 2 is = F + F ' = -0.063671 N