General Science (1st Quarter, Semester 1)

Vocabulary flashcards covering fundamental physics concepts—laws of motion, energy, work, power, momentum, thermodynamics, units, and key formulas—from the General Science (1st Quarter) lecture notes.

Physics

The branch of science that studies matter, energy, motion, and the interactions between them.

Isaac Newton

Physicist who formulated the three laws of motion and discovered universal gravitation.

Force

A push or pull that can change an object’s motion; calculated by F = m × a (newton).

Mass

The amount of matter in an object; quantitative measure of inertia (kilogram).

Acceleration

Change in velocity per unit time (m s²).

Deceleration

Negative acceleration; velocity decreases over time.

Contact Force

A force that arises from physical touch between two objects (e.g., friction, normal).

Non-Contact Force

A force that acts at a distance without physical contact (e.g., gravity, electric, magnetic).

Inertial Reference Frame

A frame of reference in which Newton’s first law holds and no fictitious forces appear.

Newton’s First Law (Inertia)

An object remains at rest or in uniform motion unless acted upon by an external force.

Newton’s Second Law (Acceleration)

Acceleration is proportional to net force and inversely proportional to mass (F = m a).

Newton’s Third Law (Interaction)

For every action force there is an equal and opposite reaction force on a different body.

Speed of Light

Exact value 299 792 458 m s²; fundamental speed limit constant in all reference frames.

Einstein’s Equation (E = mc²)

Relates energy to mass times the speed of light squared, showing mass-energy equivalence.

Energy

Capacity to do work; cannot be created or destroyed, only transformed (joule).

Kinetic Energy

Energy of motion; KE = ½ m v².

Potential Energy

Stored energy due to position or condition; gravitational PE = m g h.

Work

Product of force and displacement in the direction of the force (W = F × d, joule).

Power

Rate of doing work or transferring energy (P = W⁄t, watt).

Positive Work

Work done when force and motion are in the same direction (e.g., lifting a weight).

Negative Work

Work done when force and motion are in opposite directions (e.g., catching a ball).

Momentum

Quantity of motion; product of mass and velocity (p = m v, kg m s²).

Law of Conservation of Momentum

Total momentum of a closed system remains constant before and after collision.

Impulse

Change in momentum produced by a force acting over time; J = F Δt = Δp.

Energy Transformation

Conversion of energy from one form to another (e.g., chemical → radiant in a flashlight).

First Law of Thermodynamics

Energy cannot be created or destroyed; it only changes form (conservation of energy).

Second Law of Thermodynamics

Heat flows spontaneously from hot to cold; no engine is 100 % efficient.

Machine Efficiency

Percentage ratio of output work to input work; (m g h)⁄(F d) × 100 %.

Joule (J)

SI unit of work and energy; equal to one newton-metre.

Watt (W)

SI unit of power; equal to one joule per second.

SI Unit of Force

Newton (N).

SI Unit of Mass

Kilogram (kg).

SI Unit of Acceleration

Metre per second squared (m s²).

SI Unit of Momentum

Newton-second or kilogram-metre per second (N s or kg m s²).

Unit Conversion – Mass

Metric mass uses factors of 1000: tonne ↔ kg ↔ g ↔ mg (e.g., 1.6 tonne = 1600 kg).

Gravity

Force of attraction between masses; causes spacetime curvature in general relativity.

Spacetime

Four-dimensional fabric combining space and time, bent by mass and energy.

Distance

Total path length traveled, independent of direction.

Displacement

Straight-line difference between final and initial positions; vector quantity.