University:
College
Course:
College Physics
Academic year:

2022
Views:

55

Pages:

1
Author:

Clint W.

Name ___________________________ Class __________________ Date ____________ Chapter 32 Electrostatics Coulomb’s Law Consider a pair of charged particles separated by a distance d. If the distance between the particles is multiplied by 4, how will the electrostatic force between the particles change? 1. Read and Understand What information are you given? Two charged particles, q1 and q2, are a distance d apart. An electrostatic force, F, exists between the particles. The final distance equals 4d. 2. Plan and Solve What unknown are you trying to calculate? Electrostatic force after the distance changes, Fnew = ? What mathematical relationship can you use to find the unknown? qq Coulomb’s law: F = k 1 2 2 d Apply this law to find the new force after the distance changes. qq qq Fnew = k 1 22 = k 1 22 = 1 F 16 ( 4d) 16d 3. Look Back and Check Is your answer reasonable? Yes, the distance increased by a factor of 4, so the force should decrease by a factor of 4 squared, or 16. Math Practice On a separate sheet of paper, solve the following problems. Consider a pair of particles separated by a distance d. 1. If the charge of each particle tripled and the distance also tripled, how would the electrostatic force between the particles change? Fnew = k (3 q1)(3 q2 ) = F; the force would not change. (3 d )2 2. If the charge of one particle doubled and the charge of the other particle tripled, how would the electrostatic force between the particles change? Fnew = k (2 q1)(3 q2 ) = 6F; the force would increase by a factor of 6. d2 3. If the charge of one particle were reduced to one-half the original charge and the distance between the charges were multiplied by 2, how would the electrostatic force between the particles change? ¨ 1 q ·( q ) 1¹̧ 2 ª© = 1 F; the force would be reduced by a factor of 8. Fnew = k 2 8 (2 d )2