Answer:
1.An inertial frame of reference in classical physics and special relativity possesses the property that in this frame of reference a body with zero net force acting upon it does not accelerate; that is, such a body is at rest or moving at a constant velocity.
2.In a non-inertial reference frame in classical physics and special relativity, the physics of a system vary depending on the acceleration of that frame with respect to an inertial frame, and the usual physical forces must be supplemented by fictitious forces.
3.moment-of-force. Noun. (plural moments of force) (physics) The turning effect of a force applied to a rotational system at a distance from the axis of rotation. The moment is equal to the magnitude of the force multiplied by the perpendicular distance between its line of action and the axis of rotation.
Step-by-step explanation: