11) Three point charges of magnitudes +6.0 mC, -7.0 mC, and -13 mC are placed on the x-axis at x = 0 cm, x = 40 cm, and x = 120 cm, respectively. What is the force on the -13 mC charge due to the other two charges?
A) -0.55 N B) -0.79 N
C) 0.55 N D) 0.79 N
not sure. .79N
To find the force on the -13 mC charge due to the other two charges (+6.0 mC and -7.0 mC), we can use Coulomb's law.
Coulomb's law states that the force between two charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them.
The formula for Coulomb's law is given by:
F = k * |q1 * q2| / r^2
Where F is the force, k is the electrostatic constant (8.99 x 10^9 Nm^2/C^2), q1 and q2 are the magnitudes of the charges, and r is the distance between them.
In this case, we have two charges (-13 mC and +6.0 mC) at distances of 120 cm and 40 cm, respectively, from the -13 mC charge.
Let's calculate the force:
First, convert the magnitudes of the charges to coulombs:
-13 mC = -13 x 10^-3 C
+6.0 mC = +6.0 x 10^-3 C
Next, convert the distances to meters:
120 cm = 120 x 10^-2 m
40 cm = 40 x 10^-2 m
Now, substitute the values into Coulomb's law formula:
F = (8.99 x 10^9 Nm^2/C^2) * |-13 x 10^-3 C * +6.0 x 10^-3 C| / (120 x 10^-2 m)^2
Simplifying the formula:
F = (8.99 x 10^9 Nm^2/C^2) * (13 x 6.0 x 10^-6 C^2) / (120 x 10^-2 m)^2
F = (8.99 x 10^9 Nm^2/C^2) * (78 x 10^-6 C^2) / (120 x 10^-2 m)^2
F = (8.99 x 78) Nm² / (120²) C
F = (701.22 / 14400) N
Now, divide the numerator by the denominator:
F = 0.0486375 N
The calculated force on the -13 mC charge due to the other two charges is approximately 0.0486 N.
Therefore, the correct answer among the options provided is not listed.