Final answer:
During a high-speed turn, a jet pilot experiences what feels like a centrifugal force, which is a reactive force to the centripetal force necessary for circular motion.
The correct option is 1. centrifugal force.
Step-by-step explanation:
The term a jet pilot might use to describe the force that presses him against his seat during a high-speed turn is centrifugal force. Even though from the pilot's perspective it feels like being pushed outward from the center of the turn, a physicist would describe this as a reactive force to the centripetal force, which is the actual force acting towards the center that keeps the pilot in a circular path.
When turning, the pilot experiences this apparent force due to the non-inertial frame of reference of the accelerating jet. Centrifugal force is not a real force; it results from the inertia of the pilot's body attempting to continue in a straight line while the jet turns.
centrifugal force is the correct answer.