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Two point charges 1.7 cm apart have an electric potential energy of -180 μJ. The total charge is 34 nC.

a. -1 μC, 35 μC
b. -17 μC, 17 μC
c. -2 μC, 36 μC
d. -18 μC, 16 μC

User Andir
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1 Answer

4 votes

Final answer:

The internal energy of a system consisting of two point charges can be calculated using the formula U = k * (q1 * q2) / r. By rearranging the formula and substituting the given values, we can solve for the charges. In this case, the charges are -17 μC and 17 μC.

Step-by-step explanation:

The internal energy of a system of two point charges can be calculated using the formula:

U = k * (q1 * q2) / r

where U is the electric potential energy, k is the electrostatic constant (9 x 10^9 Nm^2/C^2), q1 and q2 are the charges, and r is the distance between the charges.

In this case, we have the values of U and r, and we want to find the charges. Rearranging the formula, we can solve for q1 * q2:

q1 * q2 = (U * r) / k

Substituting the given values into the equation:

q1 * q2 = (-180 x 10^-6 J * 1.7 x 10^-2 m) / (9 x 10^9 Nm^2/C^2)

q1 * q2 = -3.06 x 10^-15 C^2

Since the total charge in the system is 34 x 10^-9 C, we can solve for q1 and q2:

q1 + q2 = 34 x 10^-9 C

q1 - 3.06 x 10^-15 C = 34 x 10^-9 C

q1 = 34 x 10^-9 C + 3.06 x 10^-15 C

q1 = 34 x 10^-9 C

q2 = 34 x 10^-9 C - 34 x 10^-9 C

q2 = 0 C

Therefore, the answer is b. -17 μC, 17 μC.

User Jimjampez
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