| Term | Definition |
|---|---|
| angular velocity | The rate at which an object or system rotates, measured as the change in angular position per unit 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. |
| rigid system | A system that holds its shape but in which different points on the system move in different directions during rotation. |
| rotational inertia | A measure of a rigid system's resistance to changes in its rotational motion, dependent on both the mass of the system and how that mass is distributed relative to the axis of rotation. |
| rotational kinetic energy | The kinetic energy possessed by a rigid system due to its rotation about an axis, calculated as K = 1/2 I ω². |
| scalar | A physical quantity that has magnitude only, without direction. |
| translational kinetic energy | The kinetic energy associated with the linear motion of an object's center of mass. |
| Term | Definition |
|---|---|
| angular displacement | The measurement of the angle, in radians, through which a point on a rigid system rotates about a specified axis. |
| angular position | The rotational location of an object, typically measured as an angle from a reference direction. |
| rigid system | A system that holds its shape but in which different points on the system move in different directions during rotation. |
| torque | A measure of the rotational effect of a force on a rigid system, calculated as the product of the force and its perpendicular distance from the axis of rotation. |
| work | The amount of energy transferred into or out of a system by a force exerted on that system over a distance. |
| Term | Definition |
|---|---|
| angular acceleration | The rate of change of angular velocity with respect to time. |
| angular impulse | The product of the torque exerted on an object or rigid system and the time interval during which the torque is exerted, calculated as τΔt. |
| angular momentum | A measure of the rotational motion of an object or system, calculated as the product of moment of inertia and angular velocity, or as the product of mass, velocity, and perpendicular distance from a reference point. |
| angular velocity | The rate at which an object or system rotates, measured as the change in angular position per unit time. |
| impulse-momentum theorem | A principle relating the impulse applied to an object to its change in momentum; in rotational form, it relates angular impulse to change in angular momentum. |
| 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. |
| radial distance | The perpendicular distance from a reference point or axis to an object. |
| rigid system | A system that holds its shape but in which different points on the system move in different directions during rotation. |
| rotational inertia | A measure of a rigid system's resistance to changes in its rotational motion, dependent on both the mass of the system and how that mass is distributed relative to the axis of rotation. |
| torque | A measure of the rotational effect of a force on a rigid system, calculated as the product of the force and its perpendicular distance from the axis of rotation. |
| Term | Definition |
|---|---|
| angular impulse | The product of the torque exerted on an object or rigid system and the time interval during which the torque is exerted, calculated as τΔt. |
| angular momentum | A measure of the rotational motion of an object or system, calculated as the product of moment of inertia and angular velocity, or as the product of mass, velocity, and perpendicular distance from a reference point. |
| angular momentum transfer | The process by which angular momentum is exchanged between a system and its environment when net external torque is nonzero. |
| angular speed | The rate at which an object or system rotates about a rotational axis, measured in radians per unit time. |
| axis of rotation | The fixed line about which a system rotates. |
| conservation of angular momentum | The principle that the total angular momentum of a system remains constant when the net external torque is zero. |
| net external torque | The total rotational force applied to a system from outside sources. |
| nonrigid system | A system whose shape or configuration can change, allowing mass to move closer to or further from the rotational axis. |
| rigid system | A system that holds its shape but in which different points on the system move in different directions during rotation. |
| system | A collection of objects and their interactions that are studied together as a single unit. |
| Term | Definition |
|---|---|
| angular acceleration | The rate of change of angular velocity with respect to time. |
| angular displacement | The measurement of the angle, in radians, through which a point on a rigid system rotates about a specified axis. |
| angular velocity | The rate at which an object or system rotates, measured as the change in angular position per unit 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. |
| energy dissipation | The process by which mechanical energy is converted to other forms (such as heat) and removed from a system. |
| friction | A nonconservative force that opposes motion and dissipates mechanical energy. |
| kinetic energy | The energy possessed by an object due to its motion, equal to one-half the product of its mass and the square of its velocity. |
| kinetic friction | The friction force that acts between two surfaces when they are in contact and moving relative to each other. |
| rolling | Motion of a system that combines both translational motion of its center of mass and rotational motion about its center of mass. |
| rolling without slipping | Motion of a rolling object where the contact point with the surface has zero velocity, meaning the translational and rotational motions are related by the constraint that the distance traveled by the center of mass equals the arc length rotated. |
| rotational kinetic energy | The kinetic energy possessed by a rigid system due to its rotation about an axis, calculated as K = 1/2 I ω². |
| rotational motion | Motion of an object or system rotating about a fixed axis, characterized by angular displacement, angular velocity, and angular acceleration. |
| slipping | A situation in which two surfaces in contact are moving relative to each other. |
| translational kinetic energy | The kinetic energy associated with the linear motion of an object's center of mass. |
| translational motion | Motion of an object's center of mass through space, described by the displacement, velocity, and acceleration of the center of mass. |
| Term | Definition |
|---|---|
| angular momentum | A measure of the rotational motion of an object or system, calculated as the product of moment of inertia and angular velocity, or as the product of mass, velocity, and perpendicular distance from a reference point. |
| circular orbits | Orbital paths where a satellite maintains a constant distance from the central object, resulting in constant speed and energy. |
| conservation laws | Physical principles stating that certain quantities (such as energy and angular momentum) remain constant in an isolated system. |
| elliptical orbits | Orbital paths where a satellite's distance from the central object varies, causing changes in speed and kinetic energy while total mechanical energy remains constant. |
| escape velocity | The minimum velocity required for a satellite to escape the gravitational pull of a central object, achieved when the system's total mechanical energy equals zero. |
| 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. |
| gravitational potential energy | The potential energy of a system due to the gravitational interaction between two masses separated by a distance. |
| kinetic energy | The energy possessed by an object due to its motion, equal to one-half the product of its mass and the square of its velocity. |
| total mechanical energy | The sum of kinetic and potential energy in a system; remains constant in both circular and elliptical orbits. |