AP Physics C Mechanics Vocabulary

Kinematics - The study of motion without considering the forces that cause it

Position - The location of an object relative to a reference point

Displacement - The change in position from initial to final location

Distance - The total path length traveled

Velocity - The rate of change of position with direction

Speed - The magnitude of velocity

Average Velocity - Total displacement divided by total time

Instantaneous Velocity - Velocity at a specific moment in time

Acceleration - The rate of change of velocity

Average Acceleration - Change in velocity divided by total time

Instantaneous Acceleration - Acceleration at a specific moment in time

Free Fall - Motion under the influence of gravity only

Projectile Motion - Two dimensional motion under constant gravitational acceleration

Horizontal Motion - Motion parallel to the ground with constant velocity

Vertical Motion - Motion perpendicular to the ground with constant acceleration

Trajectory - The path followed by a projectile

Range - The horizontal distance traveled by a projectile

Maximum Height - The highest vertical point reached by a projectile

Relative Velocity - Velocity measured with respect to another moving object

Frame of Reference - The coordinate system from which motion is observed

Inertial Frame - A reference frame where Newtons laws hold

Noninertial Frame - An accelerating frame where fictitious forces appear

Newton First Law - An object remains at rest or in uniform motion unless acted on by a net force

Newton Second Law - Net force equals mass times acceleration

Newton Third Law - Every force has an equal and opposite reaction force

Net Force - The vector sum of all forces acting on an object

Mass - The measure of inertia of an object

Inertia - Resistance to changes in motion

Weight - The force of gravity acting on an object

Normal Force - The support force exerted by a surface

Tension - The pulling force transmitted through a string or rope

Friction - A force that opposes relative motion between surfaces

Static Friction - Friction that prevents motion between surfaces

Kinetic Friction - Friction that opposes sliding motion

Coefficient of Friction - A constant relating frictional force to normal force

Spring Force - The restoring force exerted by a spring

Drag Force - A resistive force from motion through a fluid

Equilibrium - A state in which net force is zero

Translational Equilibrium - No net force and no linear acceleration

Constraint Force - A force that restricts motion in a system

Work - Energy transferred by a force acting through a displacement

Kinetic Energy - The energy of motion

Potential Energy - Stored energy due to position or configuration

Gravitational Potential Energy - Energy stored due to height in a gravitational field

Elastic Potential Energy - Energy stored in a stretched or compressed spring

Work Energy Theorem - Net work equals the change in kinetic energy

Conservative Force - A force whose work is path independent

Nonconservative Force - A force whose work depends on path

Mechanical Energy - The sum of kinetic and potential energy

Conservation of Energy - Total energy remains constant in an isolated system

Power - The rate at which work is done

Instantaneous Power - The rate of energy transfer at a specific moment

Momentum - Mass times velocity

Linear Momentum - The quantity of motion of an object

Impulse - Force multiplied by time equal to change in momentum

Impulse Momentum Theorem - Impulse equals change in momentum

Conservation of Momentum - Total momentum remains constant in an isolated system

Center of Mass - The average position of mass in a system

System - A collection of objects treated as one unit

Internal Force - A force between objects within a system

External Force - A force exerted on a system by something outside it

Collision - An interaction where objects exert large forces over short times

Elastic Collision - A collision in which momentum and kinetic energy are conserved

Inelastic Collision - A collision in which momentum is conserved but kinetic energy is not

Perfectly Inelastic Collision - A collision in which objects stick together after impact

Explosion - An event where one object separates into multiple pieces due to internal forces

Rotation - Motion about an axis

Angular Position - The rotational location of an object

Angular Displacement - The change in angular position

Angular Velocity - The rate of change of angular position

Angular Acceleration - The rate of change of angular velocity

Rigid Body - An object whose shape does not deform

Torque - The rotational equivalent of force

Lever Arm - The perpendicular distance from axis to line of force

Moment Arm - Another term for lever arm

Moment of Inertia - Rotational inertia depending on mass distribution

Rotational Inertia - Resistance to angular acceleration

Rotational Equilibrium - Net torque equals zero

Newton Second Law for Rotation - Net torque equals moment of inertia times angular acceleration

Angular Momentum - Rotational equivalent of linear momentum

Conservation of Angular Momentum - Total angular momentum remains constant if net external torque is zero

Rotational Kinetic Energy - The energy of rotational motion

Rolling Motion - Combined translational and rotational motion

Rolling Without Slipping - Rolling where the point of contact has zero relative velocity

Axis of Rotation - The line about which an object rotates

Simple Harmonic Motion - Periodic motion with restoring force proportional to displacement

Oscillation - Repetitive back and forth motion

Amplitude - Maximum displacement from equilibrium

Period - Time for one complete cycle

Frequency - Number of cycles per unit time

Angular Frequency - Rate of oscillation in radians per second

Phase - The position in a cycle at a given time

Phase Constant - Initial phase angle in oscillatory motion

Restoring Force - A force that returns a system to equilibrium

Hooke Law - Spring force is proportional to displacement and opposite in direction

Spring Constant - A measure of spring stiffness

Pendulum - A mass swinging under gravity

Simple Pendulum - A point mass suspended from a massless string

Physical Pendulum - A rigid body oscillating about a pivot

Damping - Loss of energy causing oscillations to decrease