Three charges are on a line. A positive charge is on the far left labeled q Subscript 1 baseline positive 6 Coulombs. The second charge is 2 m away and is labeled q Subscript 2 baseline negative 4 Coulombs. The third charge is 1 m away and is labeled q Subscript 3 baseline = positive 3 Coulombs.

What is the electrical force between q2 and q3?

Recall that k = 8.99 × 109 N•meters squared over Coulombs squared..

1.0 × 1011 N
–1.1 × 1011 N
–1.6 × 1011 N
1.8 × 1011 N

1 answer

To calculate the electrical force between charges \( q_2 \) and \( q_3 \), we can use Coulomb's Law, which is given by the formula:

\[ F = k \frac{|q_1 q_2|}{r^2} \]

where:

  • \( F \) is the magnitude of the electrical force,
  • \( k = 8.99 \times 10^9 , \text{N} \cdot \text{m}^2/\text{C}^2 \) (Coulomb's constant),
  • \( q_1 \) and \( q_2 \) are the two charges,
  • \( r \) is the distance between the charges.

In this case:

  • \( q_2 = -4 , \text{C} \)
  • \( q_3 = 3 , \text{C} \)
  • The distance between \( q_2 \) and \( q_3 \) is \( 1 , \text{m} \) (as given).

Substituting the values into Coulomb's Law:

\[ F = k \frac{|(-4) \cdot 3|}{(1)^2} \] \[ F = 8.99 \times 10^9 \frac{|-12|}{1} \] \[ F = 8.99 \times 10^9 \times 12 \] \[ F = 1.0788 \times 10^{11} , \text{N} \]

Since \( q_2 \) is negative and \( q_3 \) is positive, the force will be attractive. Therefore, we will represent the force as negative.

Thus, the electrical force \( F_{23} \) between \( q_2 \) and \( q_3 \) is:

\[ F_{23} = -1.0788 \times 10^{11} , \text{N} \]

Rounded to two significant figures, this yields approximately:

\[ F_{23} \approx -1.1 \times 10^{11} , \text{N} \]

The answer is:

–1.1 × 10¹¹ N.