Identifying a Force Couple in Physics

Steps:

• Recall that a couple consists of two equal, opposite, parallel forces separated by a distance, producing pure rotation without translation.
• Examine each diagram for two forces of equal magnitude and opposite direction that are parallel but offset.
• Verify the forces do not act along the same line or cancel translationally.
• Select the diagram matching this exact configuration.

Why A is correct:

• Diagram A depicts two equal, opposite, parallel forces separated by a perpendicular distance, aligning with the definition of a couple that generates torque via the formula τ = F × d.

Why the others are wrong:

• B shows a single force, lacking the pair required for a couple.
• C illustrates concurrent forces meeting at a point, resulting in net force rather than pure torque.
• D displays equal opposite forces along the same line, forming a zero net force and torque, not a couple.

Final answer: A