All the laws

Newton's laws of motion

1. An object's velocity will remain constant unless acted on by an external force
2. Force ∝ rate of change of momentum: $$F ∝ \frac{\Delta p}{\Delta t}$$
3. Every action has an equal and opposite reaction: 🤜🤛

Kirchhoff's laws

1. Current into a point = current out of the point, i.e. $$I_{in} = I_{out}$$
2. Total EMF = Total PD, i.e. $$\Sigma\varepsilon = \Sigma V$$

Ideal gas laws

Boyle's law

Volume is inversely proportional to pressure (with constant temperature)

$$V ∝ \frac{1}{\rho}$$

Charles's law

Volume is directly proportional to temperature (with constant pressure)

$$V ∝ T$$

Pressure law

Basically a combination of the two laws above.

Pressure is directly proportional to temperature (with constant volume)

$$P ∝ T$$

Kepler's laws of planetary motion

1. Planets orbit in an ellipse, with the sun at one focus
2. The area swept out by any planet during a given time period is constant
3. $$T^2 ∝ r^3$$

Electromagnetic induction

Faraday's law of electromagnetic induction

Induced EMF equals the rate of change of magnetic flux, i.e.

$$\varepsilon = -\frac{\Delta(N\phi)}{\Delta t}$$