According to the principles of motion, an object acted upon by an external force will experience a change in motion according to what?

• A. Mass and Speed
• B. Force and Mass
• C. Time and Velocity
• D. Momentum and Resistance

Answer: (B)

The correct answer focuses on the fundamental relationship described by Newton's second law of motion, which states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. This principle can be summarized by the formula F=ma, where F represents force, m represents mass, and a represents acceleration.

When an external force is applied to an object, the change in the object's motion—whether that is its speed, direction, or both—is dependent on both the magnitude of the force and the mass of the object. A larger force results in greater acceleration, while a larger mass requires more force to achieve the same acceleration. This law is foundational in understanding motion in both static and dynamic systems, making it essential for aircrewman training and operations.

The other options relate to concepts that are important within the realm of physics but do not accurately reflect the direct relationship stated by Newton's second law. For example, mass and speed alone do not capture the dynamics of force influencing motion, just as time and velocity or momentum and resistance do not provide the necessary framework for understanding the effects of external forces on an object's motion.