Chapter 2 Motion — Vocabulary Flashcards

Vocabulary flashcards covering key motion concepts from Chapter 2, including speed, velocity, acceleration, forces, gravity, and projectile motion.

Motion

Change in position of an object over time.

Position

Location of an object in space at a given time.

Distance

Total length of the path traveled.

Time

Duration over which motion occurs.

Speed

Rate at which position changes; speed = distance ÷ time.

Instantaneous Speed

Speed at a specific moment.

Velocity

Speed with a specified direction; a vector quantity.

Instantaneous Velocity

Velocity at a specific moment.

Displacement

Change in position; a vector from start to end.

Scalar

A quantity described by magnitude only.

Vector

A quantity described by magnitude and direction.

Magnitude

Size or amount of a vector.

Direction

Orientation of a vector.

Acceleration

Change in velocity over time; a vector.

Instantaneous Acceleration

Acceleration at a specific moment.

Constant Acceleration

Acceleration that remains the same over time.

Gravity (g)

Acceleration due to Earth's gravity, about 9.80 m/s^2 downward.

Mass

Amount of matter; measure of inertia.

Inertia

Resistance to changes in motion.

Weight

Gravitational force on an object, W = m g.

Net Force

Vector sum of all forces acting on an object.

Force

Interaction that can cause a change in motion.

Newton's First Law

A body at rest stays at rest, and a moving body stays in motion unless acted on by a net external force.

Newton's Second Law

F = m a; acceleration is proportional to net force and inversely proportional to mass.

Newton's Third Law

For every action, there is an equal and opposite reaction; forces come in pairs.

Normal Force

Perpendicular contact force exerted by a surface.

Friction

Force that opposes motion between surfaces; can be static or kinetic.

Static Friction

Friction that prevents motion up to a maximum value.

Kinetic (Sliding) Friction

Friction when surfaces slide past each other.

Air Resistance

Friction from air opposing motion; drag increases with speed.

Terminal Velocity

Velocity when drag equals weight; net force is zero and acceleration stops.

Universal Gravitation

Any two masses attract; gravity follows an inverse-square law.

Big G

Gravitational constant (~6.67 × 10^-11 N m^2/kg^2) used in F = G m1 m2 / r^2.

Inverse-Square Law

Forces vary as 1/r² with distance.

Centripetal Force

Inward force causing circular motion.

Centripetal Acceleration

Acceleration toward the circle's center; a_c= v²/r It occurs when an object moves in a circular path, maintaining a constant speed while changing direction.

Uniform Circular Motion

Motion around a circle at constant speed with changing direction.

Projectile Motion

Motion under gravity with horizontal velocity constant and vertical velocity changing.

Trajectory

Path followed by a moving object.

Parabola

Shape of a projectile's path ignoring air resistance.