Final answer:
The magnitude of the unknown charge is approximately 1.2 × 10^-9 C.
Step-by-step explanation:
To calculate the magnitude of the unknown charge, we can use the equation F = qE, where F is the force, q is the charge, and E is the electric field strength.
Given that there is an upward force of 0.900 N on the unknown charge located 0.500 m below the first charge, and the first charge has a magnitude of -0.590 μC, we can calculate the magnitude of the unknown charge as follows:
F = qE
F = (-0.590 μC)(9 × 10^8 N/C)
0.900 N = q(9 × 10^8 N/C)
q ≈ 1.2 × 10^-9 C
Therefore, the magnitude of the unknown charge is approximately 1.2 × 10^-9 C.