Physics

Density Equation and Unit

ρ=m/v (g/m³ or kg/m³)

Weight Equation and Unit

w=mg (N)

Constant Speed Equation and Unit

v=d/t (m/s)

Acceleration Equation and Unit

a=(v-u)/t (m/s²)

Hooke’s Law equation and Unit

F = kx N (Newtons)

Newton’s 2nd law

F = ma N (Newtons)

Momentum Equation and Unit

p = mv kg·m/s (kilogram meters per second)

Hooke's Law

A physics law given by the equation $F = kx$ with SI unit Newtons ($\text{N}$), where $k$ is the spring constant ($\text{N/m}$) and $x$ is the displacement ($\text{m}$).

Newton's 2nd Law

A fundamental motion equation defined by $F = ma$, measured in Newtons ($\text{N}$).

Impulse

The change in momentum calculated as $J = F\Delta t = \Delta p = mv - mu$, measured in $\text{N}\cdot\text{s}$ or $\text{kg}\cdot\text{m/s}$, where a longer contact time means a smaller force for the same change.

Moment of Force (Torque)

The rotational force represented as $\tau = Fr$, measured in Newton meters ($\text{N}\cdot\text{m}$), where $F$ is force ($\text{N}$) and $r$ is the perpendicular distance from the pivot ($\text{m}$).

Kinetic Energy

The energy of an object due to its motion, calculated as $E_k = \frac{1}{2}mv^2$, measured in Joules ($\text{J}$).

Gravitational Potential Energy

The energy stored in an object due to its height, given by $E_p = mgh$, measured in Joules ($\text{J}$).

Work Done

The energy transferred when a force acts over a distance, expressed as $W=Fd$ measured in Joules ($\text{J}$).

Efficiency

A measure of energy conservation calculated as $\eta = \left(\frac{\text{useful energy out}}{\text{total energy in}}\right) \times 100\%$ or expressed as a dimensionless decimal between $0$ and $1$.

Power

The rate of doing work or transferring energy, defined by $P = \frac{W}{t}$ (or $P = \frac{E}{t}$), measured in Watts ($\text{W}$).

Pressure on a Surface

The force exerted per unit area on a surface, calculated as $P = \frac{F}{A}$, measured in Pascals ($\text{Pa}$).

Pressure in a Liquid

The pressure at a depth $h$ in a liquid, given by $P = \rho g h$, measured in Pascals ($\text{Pa}$), where $\rho$ is density ($\text{kg/m}^3$), $g$ is gravitational field strength ($9.81\,m/s^2$), and $h$ is depth ($\text{m}$).

Pressure in a Gas

The force per unit area exerted by gas molecules, expressed as $P = \frac{F}{A}$ or given by the ideal gas law $PV = nRT$, measured in Pascals ($\text{Pa}$).

Thermal Energy Required

The thermal energy needed to change temperature, calculated as $Q = mc\Delta T$, measured in Joules ($\text{J}$), where $m$ is mass ($\text{kg}$), $c$ is specific heat capacity ($\text{J/(kg}\cdot\text{K)}$), and $\Delta T$ is temperature change ($\text{K}$).

Wave Equation

The relationship defining wave motion, $v = f\lambda$, in meters per second ($\text{m/s}$), where $v$ is wave speed ($\text{m/s}$), $f$ is frequency ($\text{Hz}$), and $\lambda$ is wavelength ($\text{m}$).

Refractive Index

A dimensionless ratio representing optical density, calculated as $n=\frac{\sin i}{\sin r}$

Critical Angle

The angle at which total internal reflection occurs, calculated via $\sin(\theta_c) = \frac{n_2}{n_1}$ (in degrees or radians), where $n_1$ is the denser medium and $n_2$ is the less dense medium.

Frequency

The number of oscillations per second given by $f = \frac{1}{T}$, measured in Hertz ($\text{Hz}$), where $T$ is the period ($\text{s}$), representing the time for one complete oscillation.