What are the two forces that affect stability?

What are the two forces that affect stability?

• A. Center of gravity and buoyancy
• B. Center of thrust and drag
• C. Weight and displacement
• D. Momentum and buoyancy

Answer: (A)

Stability is governed by how gravity and buoyancy interact to resist tilting. Weight pulls downward through the boat’s center of gravity, while buoyancy pushes upward through the center of buoyancy. When the boat heels, the buoyant force shifts toward the lower side, creating a turning moment that tends to right the hull if the metacenter stays above the center of gravity. This downward and upward pair sets the restoring force that keeps the boat upright under small tilts. If the center of gravity is too high or the metacenter moves too low, the restoring moment weakens and stability decreases. The other choices mix forces or concepts not central to how a floating body resists tilting: propulsion thrust and drag relate to movement, and displacement or momentum are not the direct pair driving stability.

Stability is governed by how gravity and buoyancy interact to resist tilting. Weight pulls downward through the boat’s center of gravity, while buoyancy pushes upward through the center of buoyancy. When the boat heels, the buoyant force shifts toward the lower side, creating a turning moment that tends to right the hull if the metacenter stays above the center of gravity. This downward and upward pair sets the restoring force that keeps the boat upright under small tilts. If the center of gravity is too high or the metacenter moves too low, the restoring moment weakens and stability decreases. The other choices mix forces or concepts not central to how a floating body resists tilting: propulsion thrust and drag relate to movement, and displacement or momentum are not the direct pair driving stability.