# Physical laws

The most important physical laws:

### Newton’s first law:

states that a body at rest remains at rest and a body moving at a constant speed remains so, unless acted upon by a force.

Newton’s second law: states that if a force acts on an object, it accelerates in direct proportion to the force acting.

### Newton’s third law:

states that for every action there is a reaction equal in magnitude and opposite in direction.

### Archimedes’ law:

states that a body partially or completely immersed in a fluid loses weight as much as the weight of the displaced fluid.

### Lenz’s Law:

states that the direction of the induced current resists the effect generated by it.

### Coulomb’s Law:

states that the force between two charges is directly proportional to each of them and inversely proportional to the square of the distance between them.

### Ampere’s Law:

states that magnetic rotation on a closed path in a vacuum is constant and equal to the permeability constant times the current.

### Joule’s law

This law states that the heat emitted by the resistance to the passage of electric current is directly proportional to each of the time duration of the flow of this current, and is also directly proportional to the electric power.

### Graham’s Law

The scientist Thomas Graham put this law in the first half of the nineteenth century, as this scientist noticed that there is an inverse relationship between the rate of flow of gases, and the square root of the molar mass of gaseous molecules, and this law was formulated with a clear mathematical equation.

### Gas Laws

A set of laws developed by a number of scientists describing the relationship between temperature, pressure, and volume for gases.

### Boyle’s Law

It states: “At constant temperature T, the volume of a gas, V, is inversely proportional to its pressure, P”. P1V1=P2V2

### Charles’ Law

It states: “At constant pressure P, the volume of gas V is directly proportional to the temperature T, measured in Kelvin. V1/T1=V2/T2

### Gay-Lussac’s Law

It states, “At constant volume V, gas pressure P is directly proportional to temperature T, measured in Kelvin.” P1/T1=P2/T2