Final answer:
The question's requested magnitude of the force at x = -0.800 m cannot be calculated without the specific force-position function or more information about the system described.
Step-by-step explanation:
The question asks about the magnitude of the force on a particle at a certain position (x = -0.800 m). To find this, we would generally need the function that gives us the force as a function of the position (x). However, without a specific force-position relationship or additional information, we can't calculate the exact force. For a charge in an electric field, the force can be calculated using Coulomb's law if the electric field strength is known: F = qE, where F is the force, q is the charge, and E is the electric field strength. If the question is related to a magnetic field affecting a charged particle, the force can be calculated using the Lorentz force equation: F = q(v x B), where F is the force, q is the charge, v is the velocity of the particle, and B is the magnetic field.