Static stability is indicated when the center of pressure is behind the center of gravity by how much?

Static stability is indicated when the center of pressure is behind the center of gravity by how much?

• A. The center of pressure behind the center of gravity by at least one body diameter
• B. The center of pressure behind the center of gravity by less than one body diameter
• C. The center of pressure ahead of the center of gravity by one body diameter
• D. The center of pressure coincides with the center of gravity

Answer: (A)

Static stability comes from having the center of gravity ahead of the center of pressure by a sufficient margin. When the center of pressure sits behind the center of gravity by at least one body diameter, the aerodynamic force acts behind the CG, creating a restoring moment if the rocket tilts. That restoring torque nudges the rocket back toward straight, stable flight. A separation of about one diameter is the practical minimum to ensure a positive stability margin; if the CP is closer or ahead of the CG, the restoring moment weakens or reverses, making the flight unstable.

Static stability comes from having the center of gravity ahead of the center of pressure by a sufficient margin. When the center of pressure sits behind the center of gravity by at least one body diameter, the aerodynamic force acts behind the CG, creating a restoring moment if the rocket tilts. That restoring torque nudges the rocket back toward straight, stable flight. A separation of about one diameter is the practical minimum to ensure a positive stability margin; if the CP is closer or ahead of the CG, the restoring moment weakens or reverses, making the flight unstable.