General Physics Comprehensive Review

Flashcards covering the fundamentals of Physics as detailed in the general, thermal, wave, electricity, magnetism, and atomic physics lecture notes.

Base quantity

A type of physical quantity that has only one SI unit, such as Mass ($kg$), Length ($m$), Time ($s$), Current ($A$), and Temperature ($K$).

Derived quantity

A type of physical quantity that can be expressed by combining suitable base quantities, such as Speed, Volume, Area, and Force.

Scalar

A physical quantity having magnitude only, including mass, length, area, volume, density, time, distance, speed, energy, temperature, current, and voltage.

Vector

A physical quantity having both magnitude and direction, including weight, displacement, velocity, acceleration, force, and moment.

Period ($T$)

The time taken for one complete oscillation, calculated using the formula $T = \frac{t}{n}$ where $t$ is the time taken for $n$ oscillations.

Distance

The total length taken between two points; it is a scalar quantity measured in metres ($m$).

Displacement

The change of position of a point in a particular direction; it is a vector quantity measured in metres ($m$).

Speed

The rate of change of distance traveled with time ($\text{Speed} = \frac{\text{Distance traveled}}{\text{Time taken}}$).

Velocity

The rate of change of displacement with time; unlike speed, it is a vector quantity.

Acceleration ($a$)

The rate of change of velocity with time, expressed by the formula $a = \frac{v - u}{t}$, where $v$ is final velocity and $u$ is initial velocity.

Free fall

The motion of an object falling where the only force acting upon it is gravity, starting from rest ($u = 0, m/s$) with an acceleration $g \thickapprox 10, m/s^2$ (ignoring air resistance).

Mass

The quantity of matter in a substance, which remains the same everywhere and is measured in kilograms ($kg$).

Weight ($w$)

The attractive force exerted on an object by gravity, which varies from place to place and is calculated as $w = mg$.

Center of gravity

The specific point in a body through which its whole weight appears to act.

Density ($D$)

The mass per unit volume of a substance, calculated by the formula $D = \frac{m}{V}$.

Inertia

The property of a body that resists a change to its motion, which is directly dependent on the mass of the object.

Newton’s First Law of Motion

The law stating that if all forces are balanced, a body at rest will stay at rest, and a moving body will keep moving at a constant speed in a straight line.

Newton’s Second Law of Motion

The law stating that unbalanced forces acting on a body produce acceleration in the direction of the force, defined by $F = ma$.

Friction

A force that acts to stop the motion of two touching surfaces, acting in the opposite direction of the motion or tendency of motion.

Hooke’s Law

The principle that the extension of a loaded spring is directly proportional to the load applied, provided the elastic limit is not exceeded.

Moment ($M$)

A turning effect of a force about a pivot, defined as the product of the force ($F$) and the perpendicular distance ($d$) from the pivot ($M = Fd$).

Principle of moment

The law for a body in equilibrium stating that the sum of clockwise moments about any point is equal to the sum of anticlockwise moments about the same point.

Work ($W$)

The product of the force ($F$) and the distance ($d$) moved in the direction of the force ($W = Fd$), measured in Joules ($J$).

Potential energy ($PE$)

Energy possessed by an object due to its position or state; gravitational potential energy is calculated as $PE = mgh$.

Kinetic energy ($KE$)

Energy possessed by an object due to its motion, calculated using the formula $KE = \frac{1}{2}mv^2$.

Power ($P$)

The rate of doing work or changing energy, measured in Watts ($W$) and calculated as $P = \frac{W}{t}$ or $P = \frac{E}{t}$.

Mechanical Advantage ($M.A.$)

The ratio of the load to the effort in a simple machine ($M.A. = \frac{\text{Load}}{\text{Effort}}$).

Velocity Ratio ($V.R.$)

The ratio of the distance moved by the effort ($d_E$) to the distance moved by the load ($d_L$) in the same time.

Efficiency

The ratio of useful work done by a machine to the total work put into it, often expressed as \text{Efficiency} = \frac{M.A.}{V.R.} \times 100[\text{%}].

Brownian motion

The continuous random zig-zag motion of particles (like smoke) caused by collisions with invisible, randomly moving air molecules.

Diffusion

The process by which different substances mix as a result of the random motions of their molecules, moving from high concentration to low concentration.

Evaporation

The change of a liquid into a gas at the surface, occurring at any temperature and resulting in a cooling effect.

Bimetallic strip

A compound bar made of two different metals riveted together that bends when heated due to the metals expanding at different rates.

Thermocouple

A thermometer made from two different metal wires twisted together; it measures temperature by reading the electric current produced at junctions of different temperatures.

Boyle’s Law

The gas law stating that for a fixed mass of dry gas at constant temperature, the product of its pressure and volume is constant ($P_1V_1 = P_2V_2$).

Charles’ Law

The law stating that the volume of a fixed mass of gas at constant pressure is directly proportional to its Kelvin temperature ($\frac{V_1}{T_1} = \frac{V_2}{T_2}$).

Conduction

The process by which heat is transmitted through a medium (especially solids) from its hotter part to its colder part via molecular vibrations.

Convection

The process in fluids where heat is transmitted by the movement of heated particles, creating a convection current.

Radiation

The flow of heat energy in the form of electromagnetic infra-red waves, which requires no medium and can occur in a vacuum.

Wavelength ($\text{·}$)

The minimum distance at which a wave repeats itself, measured in metres ($m$).

Frequency ($f$)

The number of complete waves produced per second, measured in Hertz ($Hz$).

Snell’s Law

The law of refraction stating that the ratio of the sine of the angle of incidence to the sine of the angle of refraction is a constant refractive index ($n = \frac{\text{sin } i}{\text{sin } r}$).

Critical angle

The specific angle of incidence hitting a less dense medium that results in a refraction angle of $90^\text{o}$ to the normal.

Electromotive force ($e.m.f.$)

The energy supplied to each coulomb of charge within a cell or battery, measured in Volts ($V$).

Ohm’s Law

The relationship stating that the potential difference ($V$) across a conductor is proportional to the current ($I$) flowing through it, defined as $R = \frac{V}{I}$.

Transformer

A device used to vary the voltage of an alternating current ($a.c.$) supply through electromagnetic induction between a primary and secondary coil.

Thermionic emission

The emission of electrons from a hot surface, such as a heated cathode.

Isotopes

Atoms of the same element that have the same number of protons (atomic number) but different numbers of neutrons (mass number).

Half-life

The time taken for half of the unstable nuclei in a sample of a radioactive element to decay.