Physics Lecture Notes: Kinetic Particle Model, Energy, and Dynamics

This set of flashcards covers vocabulary and key concepts from the lecture notes on the kinetic particle model of matter, types of energy stores and transfers, work and power, friction, and Newton's laws of motion.

Thermal equilibrium

Describes a state where there are no net transfers of thermal energy between substances, specifically when they have reached the same temperature.

Internal energy

An energy store that is made up of the total kinetic energy associated with the random motion of the particles and the total potential energy between the particles.

Kinetic particle model

A model stating that matter is made up of tiny particles that are in constant motion and exert forces on one another due to distributed electric charges.

Work done

The product of a constant force on an object and the distance moved by the object in the direction of the force, calculated as $W = F \times d$.

Power

The work done or energy transferred per unit time, measured in the SI unit of watts ($W$) and calculated as $P = \frac{W}{t}$ or $P = \frac{E}{t}$.

Kinetic store ($E_k$)

The energy store of any object in motion, determined by the formula $E_k = \frac{1}{2} \times m \times v^2$ where $m$ is mass and $v$ is speed.

Gravitational potential store ($E_g$)

The energy store an object possesses based on its height above a reference level, calculated as $E_g = m \times g \times h$.

Principle of conservation of energy

States that energy cannot be created or destroyed, but can be transferred from one store to another, such that the total energy of an isolated system remains constant.

Friction

The contact force that opposes or tends to oppose motion between two surfaces in contact.

Resultant force ($F_{net}$)

A single overall force that has the same effect as all the individual forces acting on an object combined, calculated as $F_{net} = m \times a$.

Newton's first law of motion

States that every object will continue in its state of rest or uniform motion in a straight line unless a resultant force acts on it.

Newton's second law of motion

States that when a resultant force acts on an object of constant mass, the object will accelerate in the direction of the resultant force.

Newton's third law of motion

States that if body $A$ exerts a force on body $B$, then body $B$ will exert an equal and opposite force on body $A$.

Solid (Kinetic Properties)

A state of matter where particles are closely packed in a regular pattern and vibrate about fixed positions, possessing the least energy and highest density.

Liquid (Kinetic Properties)

A state of matter where particles are arranged in an irregular pattern and slide over each other, having a fixed volume but no fixed shape.

Gas (Kinetic Properties)

A state of matter where particles are very far apart in an irregular pattern and move freely, resulting in low density and compressibility with no fixed shape or volume.

Normal contact force

In a free body diagram, this is the force shown as an arrow perpendicular to the surface, acting from the surface upwards.

Lubricants

Substances used to make surfaces more smooth to reduce friction between moving parts.

Joule ($J$)

The SI unit used to measure energy and work done.

Watt ($W$)

The SI unit of power, equivalent to one joule of energy transferred per second.