| Term | Definition |
|---|---|
| center of mass | The point in a system where all the mass can be considered to be concentrated for the purpose of analyzing motion and forces. |
| constituent objects | The individual objects that make up a system. |
| constituent parts | The individual objects or components that make up a larger system. |
| energy transfer | The movement of energy from one part of a system to another or between a system and its environment. |
| internal structure | The arrangement and organization of constituent parts within a system that affects how the system behaves and is analyzed. |
| lines of symmetry | Imaginary lines about which a system's mass is evenly distributed, and where the center of mass is located for symmetrical objects. |
| macroscopic system | A system large enough to be observed and analyzed at the scale of everyday objects, rather than at the atomic or molecular level. |
| mass transfer | The movement of matter from one part of a system to another or between a system and its environment. |
| symmetrical mass distribution | An arrangement of mass in a system where the mass is evenly distributed about one or more lines or planes of symmetry. |
| system | A collection of objects and their interactions that are studied together as a single unit. |
| system properties | The characteristics and behaviors of a system that are determined by the interactions between objects within it. |
| Term | Definition |
|---|---|
| center of mass | The point in a system where all the mass can be considered to be concentrated for the purpose of analyzing motion and forces. |
| contact forces | Forces that result from two objects or systems physically touching each other, arising from interatomic electric forces. |
| coordinate system | A reference framework used to resolve vectors into their perpendicular components, typically using horizontal and vertical axes. |
| force | A vector quantity that describes the interaction between two objects or systems. |
| free-body diagram | A visual representation that shows all forces exerted on an object or system, with each force drawn as a vector originating from the object's center of mass. |
| interaction | The mutual influence or effect between two objects or systems, which produces a force. |
| interatomic electric forces | The electromagnetic forces between atoms that produce the macroscopic effects observed as contact forces. |
| net force | The vector sum of all forces acting on an object or system. |
| system | A collection of objects and their interactions that are studied together as a single unit. |
| vector | A quantity that has both magnitude and direction, which can be represented as the sum of perpendicular components. |
| Term | Definition |
|---|---|
| center of mass | The point in a system where all the mass can be considered to be concentrated for the purpose of analyzing motion and forces. |
| ideal pulley | A theoretical pulley with negligible mass that rotates about its center of mass with negligible friction. |
| ideal string | A theoretical string with negligible mass that does not stretch under tension and has uniform tension throughout its length. |
| internal forces | Forces that objects within a system exert on each other, which do not affect the motion of the system's center of mass. |
| Newton's third law | The principle that forces always occur in equal and opposite pairs: if object A exerts a force on object B, then object B exerts an equal and opposite force on object A. |
| paired forces | Two equal and opposite forces that result from the interaction between two objects, as described by Newton's third law. |
| tension | The macroscopic net force that segments of a string, cable, chain, or similar system exert on each other in response to an external force. |
| Term | Definition |
|---|---|
| balanced forces | Forces acting on a system that result in a net force of zero in a particular dimension. |
| inertial reference frame | A reference frame in which Newton's laws of motion apply; a frame that is either at rest or moving at constant velocity. |
| net force | The vector sum of all forces acting on an object or system. |
| Newton's first law | The principle stating that if the net force exerted on a system is zero, the velocity of that system will remain constant. |
| translational equilibrium | A state in which an object's linear velocity remains constant because the net force exerted on it is zero. |
| unbalanced forces | A configuration of forces where the net force exerted on a system is not equal to zero, resulting in acceleration. |
| vector sum | The result of adding two or more vectors together, taking into account both magnitude and direction. |
| velocity | A vector quantity that describes both the speed and direction of an object's motion. |
| Term | Definition |
|---|---|
| acceleration | The rate of change of velocity with respect to time. |
| center of mass | The point in a system where all the mass can be considered to be concentrated for the purpose of analyzing motion and forces. |
| net force | The vector sum of all forces acting on an object or system. |
| Newton's second law of motion | The principle stating that the acceleration of a system's center of mass is proportional to the net force exerted on it and occurs in the same direction as that force. |
| nonzero net external force | A net force applied to a system from outside that is not equal to zero, causing the system's velocity to change. |
| unbalanced forces | A configuration of forces where the net force exerted on a system is not equal to zero, resulting in acceleration. |
| velocity | A vector quantity that describes both the speed and direction of an object's motion. |
| Term | Definition |
|---|---|
| coefficient of kinetic friction | A dimensionless constant (μₖ) that represents the ratio of kinetic friction force to the normal force between two surfaces moving relative to each other. |
| coefficient of static friction | A dimensionless constant (μₛ) that represents the ratio of the maximum static friction force to the normal force between two surfaces. |
| friction | A nonconservative force that opposes motion and dissipates mechanical energy. |
| kinetic friction | The friction force that acts between two surfaces when they are in contact and moving relative to each other. |
| normal force | The perpendicular component of the force exerted on an object by a surface, directed away from the surface. |
| slipping | A situation in which two surfaces in contact are moving relative to each other. |
| static friction | A friction force that acts between two surfaces in contact that are not moving relative to each other, preventing an object from slipping or sliding. |
| Term | Definition |
|---|---|
| banked surface | An inclined surface on which an object travels in a circular path, where normal force and friction components contribute to centripetal acceleration. |
| centripetal acceleration | The component of an object's acceleration directed toward the center of its circular path. |
| circular orbit | The path of a satellite moving around a central body at a constant distance, where gravitational force provides the centripetal force needed to maintain the circular path. |
| circular path | The trajectory followed by an object moving in a circle around a fixed center point. |
| conical pendulum | A pendulum that moves in a horizontal circle, with tension providing a component of the centripetal force. |
| frequency | The number of complete oscillations or cycles of simple harmonic motion that occur per unit time, typically measured in hertz (Hz). |
| gravitational attraction | The force of gravity exerted by a central body on a satellite, which provides the centripetal force necessary for circular orbital motion. |
| gravitational force | The attractive force due to mass, which can serve as the sole source of centripetal acceleration at the top of a vertical circular loop. |
| Kepler's third law | A principle stating that the square of a satellite's orbital period is proportional to the cube of its orbital radius, expressed as T² = (4π²/GM)R³. |
| net acceleration | The vector sum of centripetal acceleration and tangential acceleration for an object moving in a circle. |
| normal force | The perpendicular component of the force exerted on an object by a surface, directed away from the surface. |
| orbital period | The time it takes for a satellite to complete one full orbit around a central body. |
| orbital radius | The distance from the center of a central body to a satellite in circular orbit. |
| period | The time required for an object to complete one full circular path, rotation, or cycle. |
| radius | The distance from the center of a circular path to the object traveling on that path. |
| static friction | A friction force that acts between two surfaces in contact that are not moving relative to each other, preventing an object from slipping or sliding. |
| tangential acceleration | The component of linear acceleration directed along the tangent to the circular path of a rotating point, related to angular acceleration by a_T = rα. |
| tangential speed | The instantaneous speed of an object moving along a circular path, directed tangent to the circle. |
| tension | The macroscopic net force that segments of a string, cable, chain, or similar system exert on each other in response to an external force. |
| uniform circular motion | Motion of an object traveling in a circular path at constant speed. |
| vertical circular loop | A circular path oriented vertically, where an object must maintain a minimum speed at the top to continue circular motion. |